S. S. Ay, Özer Birge, M. S. Bakır, and A. E. Yumru, “Efficacy of letrozole versus clomiphene citrate for infertile women with polycystic ovary syndrome”, Int J Reprod Contracept Obstet Gynecol, vol. 10, no. 8, pp. 2944–2949, Jul. 2021.