TY  - JOUR 
T1  - Semen analysis in fertile patients undergoing vasectomy: reference values and variations according to age, length of sexual abstinence, seasonality, smoking habits and caffeine intake
JO  - Sao Paulo Medical Journal
A1  - Sobreiro, Bernardo Passos
A1  - Lucon, Antonio Marmo
A1  - Pasqualotto, Fábio Firmbach
A1  - Hallak, Jorge
A1  - Athayde, Kelly Silveira
A1  - Arap, Sami
SN  - 1516-3180
UL  - 10.1590/S1516-31802005000400002
VL  - 123 
Y1  - 2005
PB  - Brasil 
ER  -