Teeraganok, T., J. Manonai, and P. Chongtrakool. “Vaginal health in copper intrauterine device users and non-users”. Thai Journal of Obstetrics and Gynaecology, vol. 20, no. 1, May 2012, pp. 48-53, https://he02.tci-thaijo.org/index.php/tjog/article/view/1149.