1. Adriaens, P. R., & De Block, A. (2006). The evolution of a social construction: The case of male homosexuality. Perspectives in Biology and Medicine, 49, 570–585.
2. Adriaens, P. R., De Block, A., & Newson, L. (2012). Evolutionary theory, constructionism and male homosexuality. In F. de Sousa & G. Munevar (Eds.), Sex, reproduction and Darwinism (pp. 77–94). London: Pickering & Chatto.
3. Asa, C. S., & Valdespino, C. (1998). Canid reproductive biology: An integration of proximate mechanisms and ultimate causes. American Zoologist, 38, 1387–1389.
4. Bagemihl, B. (1999). Biological exuberance: Animal homosexuality and natural diversity. New York: St. Martin’s Press.
5. Bartoš, L., & Holečková, J. (2006). Exciting ungulates: Male-male mounting in fallow, white-tailed and red deer. In V. Sommer & P. Vasey (Eds.), Homosexual behavior in animals: An evolutionary perspective (pp. 154–171). Cambridge: Cambridge University Press.