Likkasittipan, N., and B. Wiriyasirivaj. “Effect of Lidocaine Gel for Pain Relief during Endometrial Sampling: A double-blinded randomized controlled trial”. Thai Journal of Obstetrics and Gynaecology, vol. 29, no. 5, Sept. 2021, pp. 273-80, doi:10.14456/tjog.2021.32.