Nath, S., S. Dutta, and G. Kamilya. “Sildenafil Citrate Therapy in Intrauterine Growth Restriction With Oligohydramnios”. International Journal of Health and Clinical Research, vol. 4, no. 4, Feb. 2021, pp. 123-6, https://www.ijhcr.com/index.php/ijhcr/article/view/749.