1. Semen and the curse of cutoffs;Niederberger;J Urol,2011
2. WHO laboratory manual for the examination of human semen and sperm-cervical mucus interaction,1980
3. WHO laboratory manual for the examination of human semen and sperm-cervical mucus interaction,1987
4. WHO laboratory manual for the examination of human semen and sperm-cervical mucus interaction,1992
5. WHO laboratory manual for the examination of human semen and sperm-cervical mucus interaction,1999