Affandi, Biran, et al. “A Multicentred Phase III Comparatiye Study Between Single-Implant Containing 3-Ketodesogestrel (Implanon®) and Implants Containing Levonorgestrel (Norplant®) I. Eff¯cacy, Acceptability and Safety (three-Year Results)”. Medical Journal of Indonesia, vol. 8, no. 1, Jan. 1999, pp. 49-55, doi:10.13181/mji.v8i1.677.