Sangsawang, N., B. Sangsawang, and P. Wisarapun. “Attitude, awareness and characteristics of emergency contraceptive pill usage among adolescents”. Journal of Medicine and Health Sciences, vol. 23, no. 1, Apr. 2016, pp. 15-25, https://he01.tci-thaijo.org/index.php/jmhs/article/view/58598.