Difference between revisions of "Sexual sensation of the foreskin"

From IntactiWiki
Jump to navigation Jump to search
m (Nerve types: Wikify.)
(Add author.)
(21 intermediate revisions by 2 users not shown)
Line 1: Line 1:
Anatomical investigations have identified the prepuce as a primary erogenous zone in humans.<ref name="ErogenousZones">{{REFjournal
+
Anatomical investigations have identified the prepuce as a primary erogenous zone in humans.<ref name="ErogenousZones">{{WinkelmannRK 1959}}</ref> Falliers (1970) commented on the "sensory pleasure induced by tactile stimulation of the foreskin."<ref name="falliers1970">{{REFjournal
|last=Winkelmann
 
|init=RK
 
|title="The Erogenous Zones: Their nerve supply and significance"
 
|journal=Proceedings of the staff meetings of the Mayo Clinic
 
|volume=34
 
|issue=2
 
|pages=39-47
 
|url=http://www.cirp.org/library/anatomy/winkelmann/
 
|quote=
 
|pubmedID=13645790
 
|pubmedCID=
 
|DOI=
 
|date=1959
 
|accessdate=2019-09-10
 
}}</ref> Falliers (1970) commented on the "sensory pleasure induced by tactile stimulation of the foreskin."<ref name="falliers1970">{{REFjournal
 
 
  |last=Falliers
 
  |last=Falliers
 
  |first=
 
  |first=
Line 256: Line 241:
 
  |issue=4
 
  |issue=4
 
  |page=499A
 
  |page=499A
}}</ref> The [[foreskin]] is what's known as a specific erogenous zone.<ref name="ErogenousZones"/> This means that it is richly equipped with a high density and concentration of specialized and sophisticated nerve receptors that convey pleasure.<ref name="garcía-mesa2021" /> The presence of specialized nerves, nerves that do no not exist elsewhere, make this part of the [[penis]] especially important. Consequently, this has been studied in detail by respected anatomists for over a century, who have transformed their knowledge by detailed empirical observation of the nerves that are present in the [[foreskin]].
+
}}</ref> The [[foreskin]] is what's known as a ''specific erogenous zone''.<ref name="ErogenousZones"/> This means that it is richly equipped with a high density and concentration of specialized and sophisticated nerve receptors that convey pleasure.<ref name="garcía-mesa2021" /> The presence of specialized nerves, nerves that do no not exist elsewhere, make this part of the [[penis]] especially important. Consequently, this has been studied in detail by respected anatomists for over a century, who have transformed their knowledge by detailed empirical observation of the nerves that are present in the [[foreskin]].
  
 
As the most richly innervated part of the [[penis]], the [[foreskin]] has the largest number of nerve receptors, as well as the greatest variety of nerve receptors.<ref name="garcía-mesa2021"/> These specialized nerve endings include:
 
As the most richly innervated part of the [[penis]], the [[foreskin]] has the largest number of nerve receptors, as well as the greatest variety of nerve receptors.<ref name="garcía-mesa2021"/> These specialized nerve endings include:
Line 406: Line 391:
 
[[Image:Fine-Touch-Pressure-Thresholds-in-the-Adult-Penis_IntactWiki.gif|right|thumb|Fine Touch Pressure Thresholds in the Adult Penis.]]
 
[[Image:Fine-Touch-Pressure-Thresholds-in-the-Adult-Penis_IntactWiki.gif|right|thumb|Fine Touch Pressure Thresholds in the Adult Penis.]]
  
The foreskin has important sexual nerve receptors that are removed during circumcision.<ref name="CutaneousInnervation"/><ref name="ErogenousZones"/><ref name="Mucosa"/><ref name="cold1999">{{REFjournal
+
The [[foreskin]] has important sexual nerve receptors that are removed during [[circumcision]].<ref name="CutaneousInnervation"/><ref name="ErogenousZones"/><ref name="Mucosa"/><ref name="cold1999">{{REFjournal
 
  |last=Cold
 
  |last=Cold
 
  |init=CJ
 
  |init=CJ
Line 419: Line 404:
 
  |url=http://www.ncbi.nlm.nih.gov/pubmed/10349413?dopt=Abstract
 
  |url=http://www.ncbi.nlm.nih.gov/pubmed/10349413?dopt=Abstract
 
  |pubmedID=10349413
 
  |pubmedID=10349413
}}</ref> Circumcision removes the most sensitive part of a man's penis. The five most sensitive areas of the penis are on the foreskin. The transitional region from the external to the internal foreskin is the most sensitive region of the fully intact penis, and more sensitive than the most sensitive region of the circumcised penis.<ref name="FineTouchPressure">{{REFjournal
+
}}</ref> [[Circumcision]] removes the most sensitive part of a man's [[penis]]. The five most sensitive areas of the [[penis]] are on the [[foreskin]]. The transitional region from the external to the internal foreskin is the most sensitive region of the fully [[intact]] penis, and more sensitive than the most sensitive region of the [[circumcised]] [[penis]].<ref name="FineTouchPressure">{{REFjournal
 
  |last=Sorrells
 
  |last=Sorrells
 
  |first=Morris L.
 
  |first=Morris L.
Line 442: Line 427:
 
}}</ref>
 
}}</ref>
  
In a 2007 study, which was published in ''BJU International''. They physically measured the sensitivity of all the parts of the penis. They used a very accurate pressure sensing probe while the test subject, who’s view was blocked with a screen, reported a sensation of touch. To demonstrate precision they took each  measurement multiple times. To no surprise, their results corroborated with the neuro-anatomy that has been discussed previously.
+
In a 2007 study, which was published in ''BJU International''. They physically measured the sensitivity of all the parts of the [[penis]]. They used a very accurate pressure sensing probe while the test subject, who’s view was blocked with a screen, reported a sensation of touch. To demonstrate precision they took each  measurement multiple times. To no surprise, their results corroborated with the neuro-anatomy that has been discussed previously.
  
"Five locations on the [[foreskinned]] penis that are routinely removed at [[circumcision]] were more sensitive than the most sensitive location on the circumcised penis[...] The [[glans]] in the circumcised male is less sensitive to fine-touch pressure than the glans of the [[uncircumcised]] male[...]The most sensitive location on the circumcised penis is the [[circumcision scar]] on the ventral surface [...]  When compared to the most sensitive area of the circumcised penis, several locations on the [[uncircumcised]] penis that are missing from the circumcised penis were significantly more sensitive."<ref name="FineTouchPressure"/>
+
"Five locations on the [[foreskinned]] [[penis]] that are routinely removed at [[circumcision]] were more sensitive than the most sensitive location on the circumcised penis[...] The [[glans]] in the [[circumcised]] male is less sensitive to fine-touch pressure than the glans of the [[uncircumcised]] male[...]The most sensitive location on the circumcised penis is the [[circumcision scar]] on the ventral surface [...]  When compared to the most sensitive area of the [[circumcised]] [[penis]], several locations on the [[uncircumcised]] penis that are missing from the [[circumcised]] [[penis]] were significantly more sensitive."<ref name="FineTouchPressure"/>
  
 
[[Image:Sorrells_AAP.jpg|right|thumb|AAP skepticism that loss of foreskin could actually affect sex.]]
 
[[Image:Sorrells_AAP.jpg|right|thumb|AAP skepticism that loss of foreskin could actually affect sex.]]
  
== AAP brushes off findings as inconclusive ==
+
== AAP discards its former Circumcision Policy Statement ==
  
 
In the [[AAP]]'s 2012 Circumcision Task force report, the issues of sensitivity reduction were given obligatory mention but largely glossed over, and little space was devoted to the topic. The 2012 Task Force Report received [[American_Academy_of_Pediatrics#Criticism| overwhelmingly heavy critical comment]]. The purpose of the disastrous, now expired AAP 2012 report was to encourage neonatal non-therapeutic [[circumcision]] and [[third-party payment]] so little or nothing was said about the multiple functions of the [[foreskin]].<ref name="hill2013">{{REFdocument
 
In the [[AAP]]'s 2012 Circumcision Task force report, the issues of sensitivity reduction were given obligatory mention but largely glossed over, and little space was devoted to the topic. The 2012 Task Force Report received [[American_Academy_of_Pediatrics#Criticism| overwhelmingly heavy critical comment]]. The purpose of the disastrous, now expired AAP 2012 report was to encourage neonatal non-therapeutic [[circumcision]] and [[third-party payment]] so little or nothing was said about the multiple functions of the [[foreskin]].<ref name="hill2013">{{REFdocument
Line 460: Line 445:
 
  |date=2013-04-01
 
  |date=2013-04-01
 
  |accessdate=2022-04-02
 
  |accessdate=2022-04-02
}}</ref> The failed 2012 AAP Circumcision Policy expired in 2017 and has not been re-affirmed or re-validated in any way.  The AAP currently has ''no'' circumcision policy.
+
}}</ref> The failed 2012 AAP Circumcision Policy expired in 2017 and has not been re-affirmed or re-validated in any way.  The AAP currently has ''no'' circumcision policy and does ''not'' recommend [[circumcision]] of boys.
  
 
==Sorrells study of penis fine-touch sensation.==
 
==Sorrells study of penis fine-touch sensation.==
Line 470: Line 455:
 
García-Mesa et al. (2021) reported: "[s]timulation of genital
 
García-Mesa et al. (2021) reported: "[s]timulation of genital
 
Meissner's corpuscles gives rise to sexual sensations."<ref name="garcía-mesa2021" />
 
Meissner's corpuscles gives rise to sexual sensations."<ref name="garcía-mesa2021" />
 +
==The circumcised penis==
 +
The nerves and other structures mentioned in this article are largely missing on the [[circumcised]] [[penis]].
 +
 +
[[Intact]] men who elect to be [[circumcised]] frequently report very substantial loss of sensation after [[Adolescent and adult circumcision| circumcision]].
  
 
{{SEEALSO}}
 
{{SEEALSO}}
 
* [[Acroposthion]]
 
* [[Acroposthion]]
 
* [[Gliding action]]
 
* [[Gliding action]]
 +
* [[Masturbation]]
 +
* [[Pre-ejaculate]]
 +
* [[Regret men]]
 
* [[Sexual effects of circumcision]]
 
* [[Sexual effects of circumcision]]
 +
* [[Sex with phimosis]]
 +
* [[The Penis - Sex Education 101]]
  
 
{{LINKS}}
 
{{LINKS}}
 +
* {{REFbook
 +
|last=Ball
 +
|first=Peter
 +
|init=
 +
|author-link=Peter Ball
 +
|year=2006
 +
|title=A Survey of Subjective Foreskin Sensation in 600 Intact Men
 +
|url=http://eknygos.lsmuni.lt/springer/59/177-188.pdf
 +
|work=Bodily Integrity and the Politics of Circumcision
 +
|editors=[[George C. Denniston]], [[Pia Grassivaro Gallo]], [[Frederick M. Hodges]], [[Marilyn Fayre Milos]], and [[Franco Viviani]]
 +
|edition=First
 +
|volume=
 +
|chapter=Chapter 16
 +
|pages=177-188
 +
|location=
 +
|publisher=Springer
 +
|ISBN=9789048172252
 +
|quote=I believe that many women and most circumcised men are totally unaware of the role that the foreskin plays in the enjoyment of sex.
 +
|format=PDF
 +
|accessdate=2022-02-23
 +
|note=
 +
}}
 
* {{REFweb
 
* {{REFweb
 
  |url=http://www.circumstitions.com/tantra.html
 
  |url=http://www.circumstitions.com/tantra.html
Line 509: Line 525:
 
  |quote=
 
  |quote=
 
}}
 
}}
 
+
* {{REFweb
 +
|url=https://intactamerica.org/what-do-the-eyelids-lips-fingertips-the-intact-penis-have-in-common/
 +
|title=What Do The Eyelids, Lips, Fingertips & The Intact Penis Have in Common?
 +
|last=Garrett
 +
|first=Connor
 +
|init=
 +
|author-link=Connor Judson Garrett
 +
|publisher=Intact America
 +
|date=2024-02-17
 +
|accessdate=2024-02-18
 +
}}
 
{{REF}}
 
{{REF}}
  
Line 515: Line 541:
 
[[Category:Penile function]]
 
[[Category:Penile function]]
 
[[Category:Foreskin anatomy]]
 
[[Category:Foreskin anatomy]]
 +
[[Category:Sexuality]]
 +
[[Category:Male sexuality]]
 +
 
[[Category:From Intactipedia]]
 
[[Category:From Intactipedia]]
 
[[Category:From IntactWiki]]
 
[[Category:From IntactWiki]]
  
 
[[de:Vorhaut-Empfindlichkeit]]
 
[[de:Vorhaut-Empfindlichkeit]]

Revision as of 15:30, 2 June 2024

Anatomical investigations have identified the prepuce as a primary erogenous zone in humans.[1] Falliers (1970) commented on the "sensory pleasure induced by tactile stimulation of the foreskin."[2]

For over a hundred years, anatomical research has confirmed that both the penile and clitoral prepuce (foreskin) are richly innervated, specific erogenous tissue with specialised encapsulated (corpuscular) sensory receptors, such as Meissner's corpuscles,[3] Pacinian corpuscles, genital corpuscles, Krause end bulbs, Ruffini corpuscles, and mucocutaneous corpuscles. These receptors transmit sensations of fine touch, pressure, proprioception, and temperature.[4][5][6][7][8][9][10][11][1][12]

Nerve types

The two primary sensory receptors in primate skin are free nerve endings and encapsulated or corpuscular receptors. While free nerve endings (pain, itch, and temperature receptors) are found in most skin, the encapsulated receptors are concentrated in regions that require specialised touch sensitivity, such as at the fingertips, lips, external genitalia, perianal skin, and transition areas between skin and mucous membranes.[13]

The innervation of the foreskin is impressive [14] The foreskin is what's known as a specific erogenous zone.[1] This means that it is richly equipped with a high density and concentration of specialized and sophisticated nerve receptors that convey pleasure.[3] The presence of specialized nerves, nerves that do no not exist elsewhere, make this part of the penis especially important. Consequently, this has been studied in detail by respected anatomists for over a century, who have transformed their knowledge by detailed empirical observation of the nerves that are present in the foreskin.

As the most richly innervated part of the penis, the foreskin has the largest number of nerve receptors, as well as the greatest variety of nerve receptors.[3] These specialized nerve endings include:

  • free nerve endings, end bulbs of Krause,[4][16]
  • Corpuscles of Ruffini,[16]
  • Pacinian corpuscles,[6]
  • genital end bulbs [17]
  • Genital bodies,[6]
  • Merkels disks, Golgi-Mazzoni corpuscles,[6]
  • and Vater-Pacinian corpuscles.[9]

These remarkable organs provide the foreskin with its amazing ability to detect the slightest sensations of touch, motion, temperature, and pressure. We are still unaware of all the facts about these fascinating structures. Future research may discover even more nerve receptors in the foreskin and help clarify what purposes they serve. The primary zones of erogenous sensitivity are the frenulum, ridged band of mucosa, and the preputial orifice and the external fold of the foreskin. All of these zones are orgasmic triggers. Continuous gentle stimulation of any one of these areas can elicit pleasure, erection, orgasm, and ejaculation. Some men report that simple retraction of their foreskin causes erection.

Meissner's corpuscles

Meissner's corpuscle.

Distributed on various areas of the skin, but concentrated in areas especially sensitive to light touch, such as the fingers, lips, nipples and foreskin.[18][19][20][21][22] They are concentrated in areas of the body denoted as erogenous zones, which include the foreskin, clitoris, lip and nipple.[1] J. R. Taylor (1996) noted their presence in the foreskin,[15] and C.J. Cold & Taylor (1999) reported "Most of the encapsulated receptors of the foreskin are Meissner corpuscles, as they contact the epithelial basement membrane."[23] Early observations were noted by A.S. Dogiel (1893),[4] D. Ohmori (1924),[6] and H. C. Bazett (1935),[24] reported the presence of Meissner's corpuscles in the foreskin. Haiyang et al. (2005) found and measured the density of Meissner's corpuscles on the foreskin.[25] Dong et al. (2007) reported that the quantity of Meissner's corpuscles on the fused smooth mucosa of the foreskin decline with age, but not on the ridged band.[26]

Ridged Band

In 1991 the ridged band of the male prepuce was identified as a concentrated area of corpuscular receptors.[15]

Fine-touch sensitivity

Fine Touch Pressure Thresholds in the Adult Penis.

The foreskin has important sexual nerve receptors that are removed during circumcision.[9][1][15][27] Circumcision removes the most sensitive part of a man's penis. The five most sensitive areas of the penis are on the foreskin. The transitional region from the external to the internal foreskin is the most sensitive region of the fully intact penis, and more sensitive than the most sensitive region of the circumcised penis.[28]

In a 2007 study, which was published in BJU International. They physically measured the sensitivity of all the parts of the penis. They used a very accurate pressure sensing probe while the test subject, who’s view was blocked with a screen, reported a sensation of touch. To demonstrate precision they took each measurement multiple times. To no surprise, their results corroborated with the neuro-anatomy that has been discussed previously.

"Five locations on the foreskinned penis that are routinely removed at circumcision were more sensitive than the most sensitive location on the circumcised penis[...] The glans in the circumcised male is less sensitive to fine-touch pressure than the glans of the uncircumcised male[...]The most sensitive location on the circumcised penis is the circumcision scar on the ventral surface [...] When compared to the most sensitive area of the circumcised penis, several locations on the uncircumcised penis that are missing from the circumcised penis were significantly more sensitive."[28]

AAP skepticism that loss of foreskin could actually affect sex.

AAP discards its former Circumcision Policy Statement

In the AAP's 2012 Circumcision Task force report, the issues of sensitivity reduction were given obligatory mention but largely glossed over, and little space was devoted to the topic. The 2012 Task Force Report received overwhelmingly heavy critical comment. The purpose of the disastrous, now expired AAP 2012 report was to encourage neonatal non-therapeutic circumcision and third-party payment so little or nothing was said about the multiple functions of the foreskin.[29] The failed 2012 AAP Circumcision Policy expired in 2017 and has not been re-affirmed or re-validated in any way. The AAP currently has no circumcision policy and does not recommend circumcision of boys.

Sorrells study of penis fine-touch sensation.

At right is an easy-to-understand illustration of the Sorrells study[28] showing the loss of tissues. Tissues show in color their relative sensitivity thresholds to light touch. sensitive tissue. On the infographic's opposite side: The AAP's expressed skepticism (quotes from their now expired 2012 Circumcision task force report) on whether loss of all that erogenous tissue could really affect sexual enjoyment.

Arguably, claiming there's no evidence that circumcision diminishes sexual enjoyment is essentially implying the obverse: that it's perfectly safe and reasonable to assume that the human foreskin, despite evolving over millions of years, has no anatomical significance in sexual mechanics, and has zero relevance to sexual pleasure and satisfaction. That statement sounds immediately absurd, however.

García-Mesa et al. (2021) reported: "[s]timulation of genital Meissner's corpuscles gives rise to sexual sensations."[3]

The circumcised penis

The nerves and other structures mentioned in this article are largely missing on the circumcised penis.

Intact men who elect to be circumcised frequently report very substantial loss of sensation after circumcision.

See also

External links

References

  1. a b c d e REFjournal Winkelmann RK. The erogenous zones: their nerve supply and significance. Mayo Clin Proc. 21 January 1959; 34(3): 39-47. PMID. Retrieved 4 June 2021.
  2. REFjournal Falliers CJ. Circumcision. JAMA. December 1970; 214(12): 2194. PMID. Retrieved 17 November 2021.
  3. a b c d e REFjournal García-Mesa, Yolanda, García-Piqueras, Jorge, Cobo, Ramón, Martín-Cruces, José, Suazo, Iván, García-Suárez, Olivia, Feito, Jorge. Sensory innervation of the human male prepuce: Meissner's corpuscles predominate. Journal of Anatomy. October 2021; 239(4): 892-902. PMID. PMC. DOI. Retrieved 15 November 2021.
  4. a b c REFjournal Dogiel AS. Die Nervenendigungen in der Schleimhaut der äusseren Genitalorgane des Menschen [Nerve endings in a mucous membrane of external genital organs of the human] (German). Archiv für Mikroskopische Anatomie. 1893; 41: 585-612. Retrieved 21 June 2021.
  5. REFjournal Dogiel AS. [h Über die Nervenendapparate in der Haut des Menschen] [About the nerve end apparatuses in the human skin] (German). Ztschr Wiss Zool. 1903; 75: 46-111. Retrieved 21 June 2021.
  6. a b c d e REFjournal Ohmori D. Über die Entwicklung der Innervation der Genitalapparate als peripheren Aufnahmeapperat der genitalen Reflexe [About development of the innervation of the genital apparatuses as a peripheral recording device of the genital reflexes] (German). Zeitschrift für Anatomie und Entwicklungsgeschichte. 1924; 70(1): 347-410. Retrieved 21 June 2021.
  7. REFjournal Yamada K. Studies in the innervation in tenth month human embryo. Tohoku J Exper Med. 1951; 54: 151.
  8. REFjournal Yamada K. On the sensory nerve terminations in clitoris in human adult. Tohoku J Exper Med. 54: 163-174.
  9. a b c REFjournal Winkelmann RK. The cutaneous innervation of human newborn prepuce. Journal of investigative dermatology. 1956; 26(1): 53–67. PMID. Retrieved 30 April 2020.
  10. REFjournal Winkelmann RK. The mucocutaneous end-organ. Arch Dermatol. 1957; 76: 225-235. Retrieved 21 June 2021.
  11. REFjournal Krantz KE. Innervation of the human vulva and vagina: a microscopic study. Obstet Gynecol. 1958; 12: 382-96. Retrieved 21 June 2021.
  12. REFbook Butler AB, Hodos W (1996): Comparative Vertebrate Neuroanatomy: Evolution and Adaptation. Edition: 26. Wiley-Liss. ISBN 0471210056.
  13. REFbook Stenn KS, Bhawan J (1990): The normal histology of the skin, in: Pathology of the Skin. Farmer E.R. / Hood A.F. (eds.). Norwalk, CT: Appleton and Lange.
  14. REFjournal Moldwin RM, Valderrama E. Immunohistochemical analysis of nerve distribution patterns within preputial tissues. J Urol. April 1989; 141(4): 499A.
  15. a b c d REFjournal Taylor JR, Lockwood AP, Taylor AJ. The prepuce: specialized mucosa of the penis and its loss to circumcision. Br J Urol. 1996; 77: 291-5. PMID. DOI. Retrieved 23 September 2019.
  16. a b REFjournal Bazett HC, McGlone B, Williams RG, Lufkin HM. Depth, distribution and probable identification in the prepuce of sensory end-organs concerned in sensations of temperature and touch; thermometric conductivity. Archives of Neurology and psychiatry. 1 March 1932; 27(3): 489-517. Retrieved 27 April 2020.
  17. REFjournal Halata Z, Munger BL. The neuroanatomical basis for the protopathic sensibility of the human glans penis. Brain Res. 23 April 1986; 371(2): 205-230.
  18. REFjournal Cauna N, Ross LL. The fine structure of Meissner's touch corpuscles of human fingers. Journal of Cell Biology. 1960; 8(2): 467-482. DOI.
  19. REFjournal Hoffmann, et al. Meissner corpuscles and somatosensory acuity. Anat Rec A Discov Mol Cell Evol Biol. 2004; : 1138.1147.
  20. REFjournal Bongiorno, et al. Neurofibromatosis of the nipple-areolar area: a case series. Journal of Medical Case Reports. 27 December 2010; 4(22) DOI.
  21. REFbook Martini, Bartholomew (2010): Essentials of Anatomy and Physiology. Edition: 3. Pearson Benjamin Cummings.
  22. REFbook Afifi, Bergman (1998): Functional neuroanatomy: text and atlas. Edition: 16. McGraw-Hill Professional. ISBN 0070015899.
  23. REFjournal Cold CJ, Taylor JR. The prepuce. British Journal of Urology International. 1999; 83: 34-44. PMID.
  24. REFjournal Bazett HC. Methods of investigation of sensation in man and the theoretical value of the results obtained. Proc A Research Nerv Ment Dis. 1935; 15: 83-97.
  25. REFjournal Haiyang, et al. Observation of Meissner's corpuscle in abundant prepuce and phimosis. Journal of Modern Urology. 2005;
  26. REFjournal Dong, et al. Observation of Meissner's corpuscle on fused phimosis. Journal of Guangdong Medical College. 2007;
  27. REFjournal Cold CJ, Taylor JR. The prepuce. British Journal of Urology International. 1999; 83: 34-44. PMID.
  28. a b c REFjournal Sorrells ML, Snyder JD. Fine-touch pressure thresholds in the adult penis. BJU International. 22 October 2007; 99(4): 864–869. PMID. Retrieved 10 September 2019.
  29. REFdocument Hill, George: Commentary on American Academy of Pediatrics 2012 Circumcision Policy Statement PDF, Doctors Opposing Circumcision (D.O.C.). (1 April 2013). Retrieved 2 April 2022.