Telapol, K., S. Bumrungphuet, and N. Israngura Na Ayudhya. “Effect of Ethyl Chloride Spray for Pain Reduction during Amniocentesis: A non – blinded randomized controlled trial”. Thai Journal of Obstetrics and Gynaecology, vol. 26, no. 2, June 2018, pp. 75-82, doi:10.14456/tjog.2018.10.