1. Office evaluation of the subfertile male;Sigman,2009
2. Clinical evaluation and treatment of male factor infertility;Poch,2010
3. WHO laboratory manual for the examination of human semen and sperm-cervical mucus interaction;World Health Organization,2010
4. Within- and between-subject variation in semen parameters in infertile men and normal semen donors;Keel;Fertil Steril,2006
5. New WHO-reference limits - revolution or storm in a teapot?;Haidl;Asian J Androl,2011