Wataganara, T., Talungjit, P., Phithakwatchara, N., & Swasdimongkol, S. (2008). Three Dimensional Sonographic Appearances of Chinese Ring Intrauterine Device:. Siriraj Medical Journal, 60(6), 360–363. retrieved from https://he02.tci-thaijo.org/index.php/sirirajmedj/article/view/246512