Ariyati, Ira, Rahmad Mulyadi, Ponco Birowo, Budi Wiweko, and Joedo Prihartono. “Association Between Varicocele Grade and Semen Analysis Parameter”. Medical Journal of Indonesia 26, no. 4 (February 14, 2018): 270-6. Accessed January 19, 2022. http://mji.ui.ac.id/journal/index.php/mji/article/view/1623.