Semen analysis in fertile patients undergoing vasectomy: reference values and variations according to age, length of sexual abstinence, seasonality, smoking habits and caffeine intake.
Sao Paulo Med J. 2005 Jul 7;123(4):161-6. doi: 10.1590/s1516-31802005000400002.
Sao Paulo Med J. 2005.
PMID: 16389413
Free article.