1. WHO Laboratory Manual for the Examination of Human Semen and Sperm-Cervical Mucus Interaction;World Health Organisation,1980
2. WHO Laboratory Manual for the Examination and Processing of Human Semen;World Health Organization,2010
3. The role of age, environmental and occupational factors on semen density;Lepecka-Klusek;Ann. Agric. Environ. Med.,2011
4. Contribution of environmental factors to the risk of male infertility;Oliva;Hum. Reprod.,2001
5. Abstinence time and its impact on basic and advanced semen parameters;Agarwal;Urology,2016