↑ Nafzawi, Muhammad ibn Muhammad al, and Jim Colville (trans.). The Perfumed Garden of Sensual Delight. The Kegan Paul Arabia library, vol. 7. London: Kegan Paul, 1999.
↑ Westheimer, Ruth K., Sex for Dummies. For Dummies. 2nd ed., 2000. ISBN 0-7645-5302-X, 432 pages.
↑ Rogiere, Jean, The Little Book of Sex. Ulysses Press. 2001. ISBN 1-56975-305-9.
↑ Masters, Johnson (tháng 6 năm 1970). Human Sexual Inadequacy (ấn bản 1). Little Brown and Company. tr. 54. ISBN0-316-54985-1.
↑ Hooper, Anne. Anne Hooper's Kama Sutra, page 115. DK Publishing.
