Emokpae, M. A., E. Ogboru, and H. Eboh. “Female Infertility of Endocrine Origin in Warri, Delta State, Nigeria”. The Nigerian Health Journal, vol. 18, no. 2, May 2019, pp. 72-80, https://www.tnhjph.com/index.php/tnhj/article/view/380.