1. Talalaj J, Talalaj S. The strangest human sex, ceremonies and customs. Melbourne: Hill of Content; 1994.
2. Burton R. The kama sutra of Vatsayana. New York: Penguin Books; 1962. p. 247–52.
3. Winter HC An examination of the relationships between penis size and body image, genital image, and perception of sexual competency in the male. DAI-A November 1989; 50/05: 1225.
4. Masters WH, Johnson VE. Human sexual response. Boston: Little, Brown & Co; 1966.
5. Masters WH, Johnson VE. Human sexual inadequacy. Boston: Little, Brown; 1970.