Abid Z, Yousuf S, Qureshi F, Rizvi SM, Ommid M, Qureshi F, Masood A. Comparison of butorphanol-drotaverine versus tramadol-drotaverine as labour analgesics: an observational comparative study. Int J Reprod Contracept Obstet Gynecol [Internet]. 2025 Jul. 29 [cited 2025 Oct. 26];14(8):2636-42. Available from: https://www.ijrcog.org/index.php/ijrcog/article/view/15677