Raheja, A., Agarwal, K., Pachori, R. and Gandhi, G. 2019. Tramadol versus placebo for labor analgesia in low risk women: a randomized controlled trial. International Journal of Reproduction, Contraception, Obstetrics and Gynecology. 9, 1 (Dec. 2019), 342–347. DOI:https://doi.org/10.18203/2320-1770.ijrcog20196045.