Dahal, P., B. Banerjee, D. Uprety, B. Das, A. Thakur, and A. Agrawal. “Comparative Study of Efficacy of Drotaverine Hydrochloride and Valethamate Bromide With Control in First Stage of Labour”. Health Renaissance, vol. 11, no. 1, Feb. 2013, pp. 38-42, doi:10.3126/hren.v11i1.7600.