Townsend, J. M. (1987). “Sex differences in sexuality among medical students: Effects of increasing socioeconomic status”. Archives of Sexual Behavior16 (5): 425–444. doi:10.1007/BF01541424. PMID3689109.
Townsend, J. M. (1987). “Sex differences in sexuality among medical students: Effects of increasing socioeconomic status”. Archives of Sexual Behavior16 (5): 425–444. doi:10.1007/BF01541424. PMID3689109.
K.Grammer, Human courtship behaviour : "Biological basis and congnitive processing" In:Rasa,A.E.,Vogel,C.and Voland,E.(eds.):The Sociobiology of Sexual and Reproductive Strategies Chapmann and Hall,1989,NewYork.