here's a start
Edström, AML, Malm J, Frohm B (2008). "The major bactericidal activity of human seminal plasma is zinc-dependent and derived from fragmentation of the semenogelins.". J Immunol 181 (5): 3413–21. PMID 18714013.
Canale D, Bartelloni M, Negroni A, Meschini P, Izzo P.L, Bianchi B, Menchini-Fabris G.F (December 1986). "Zinc in human semen". International Journal of Andrololgy 9 (6): 477–80. Retrieved 4 October 2010