Rahman, M.N. et al. 2026. Clinical Performance and Levonorgestrel Levels of Sinoplant and Indoplant after Five Years of Continuous Use. Indonesian Journal of Obstetrics and Gynecology. 14, 3 (Jul. 2026), 285–295. DOI:https://doi.org/10.32771/inajog.v14i3.3121.