Bagemihl, Bruce (2000). Biological Exuberance: Animal Homosexuality and Natural Diversity. New York: St Martin’s Press
Balthazart, Jacques (2010). Biologíe de l’homosexualité. On naît homosexuel, on ne choisit pas de l´être. Wavre-Bélgica: Mardaga
Balthazart, Jacques (2010). Biologíe de l’homosexualité. On naît homosexuel, on ne choisit pas de l´être. Wavre-Bélgica: Mardaga
De Waal, Frans & Frans Lanting (1997). Bonobo. The Forgotten Ape. Berkeley: University of California Press
Gayle, Damien (2012) “Female bonobos put on 'barsexual' displays with each other to impress the alpha-lesbians”. The Daily Mail, March 2
Gayle, Damien (2012) “Female bonobos put on 'barsexual' displays with each other to impress the alpha-lesbians”. The Daily Mail, March 2
Owen, James (2004). “Homosexual Activity Among Animals Stirs Debate”. National Geographic News, July 23