Chen J, Gefen A, Greenstein A, Matzkin H, Elad D (December 2000). "Predicting penile size during erection". Int. J. Impot. Res. 12 (6): 328–33. doi:10.1038/sj.ijir.3900627. PMID11416836.
Moller, A. P. (1988). "Ejaculate quality, testes size and sperm competition in primates". Journal of Human Evolution. 17 (5): 479–488. doi:10.1016/0047-2484(88)90037-1.
Simmons, Leigh W.; Firman, Renée C.; Rhodes, Gillian; Peters, Marianne (2003). "Human sperm competition: testis size, sperm production and rates of extra pair copulations". Animal Behaviour. 68 (2): 297–302. doi:10.1016/j.anbehav.2003.11.013. S2CID52483925.
Simmons, Leigh W.; Firman, Renée C.; Rhodes, Gillian; Peters, Marianne (2003). "Human sperm competition: testis size, sperm production and rates of extra pair copulations". Animal Behaviour. 68 (2): 297–302. doi:10.1016/j.anbehav.2003.11.013. S2CID52483925.
Moller, A. P. (1988). "Ejaculate quality, testes size and sperm competition in primates". Journal of Human Evolution. 17 (5): 479–488. doi:10.1016/0047-2484(88)90037-1.