REFERENCES
- Tzvetkova, P.D. 2006. Ph. D. thesis. IEMAM-BAS, Sofia
- Tzvetkova et al.. (2008) Androl 1:14–21
- Amann et al.. (1993) J Androl 14:397–406
- Bellabara et al.. (2000) Arch Androl 45:131–136
- Hafez E (2003) Male infertility. In: Humana Reprodukcija. Bojovic S. (ed) Beograd, pp 25–53
- Hillier et al.. (1990) Obstet Gynecol 75:800–804
- Hossain et al.. (1997) Arch Androl 39:111–117
- Klein et al.. (1991) Arch Path Lab 116:11–15
- Kjaergaard et al.. (1997) Acta Obstet Gynecol 76: 528–531
- Mortimer et al.. (1982) Arch Androl 8:165–171
- Schirren, (1971) Practical Andrology. Berlin: BRUDER Hartmann
- Sigman et al.. (1993) J Urol1 49:1338–1340
- Thakur et al.. (1998) Ind J Pathol & Mcrobiol 41:343–350
- Williams W (1970) Fertil Steril 21:222–223
- Wilson L (1987) Proc Roy Soc Med 98:652–655
- Word Health Organization: WHO Laboratory manual for the examination of Human semen and semen. New York: Cambridge University Press, 1992