Septifani, Eza Azhara, Rina Desni Yetti, and Ridho Asra. “Review: The Discovery and Development of Sildenafil Citrate”. Asian Journal of Pharmaceutical Research and Development 9, no. 4 (August 15, 2021): 108–117. Accessed April 29, 2024. https://ajprd.com/index.php/journal/article/view/1018.