A. M. Muhammad, A. Habibullah, I. A. Muhammad, A. Muhammed, U. N. Nakakana, and H. T. Muhammad, “Knowledge of modern contraceptives among undergraduate students of College of Health Sciences of Usmanu Danfodiyo University Sokoto, Nigeria”, Int J Reprod Contracept Obstet Gynecol, vol. 7, no. 6, pp. 2100–2105, May 2018.