Venkat Rao, P., K. Vasu, S. Sujatha, K. Kishore Kumar, and G. Vidya Sagar. “New Spectrophotometric Methods for Sildenafil Citrate”. Asian Journal of Chemistry 18, no. 4 (July 21, 2012): 2475–2478. Accessed July 23, 2024. https://asianpubs.org/index.php/ajchem/article/view/20603.