1. Bayer HealthCare Pharmaceuticals Inc. Mirena prescribing information. 2013. Available at: http://labeling.bayerhealthcare.com/html/products/pi/Mirena_PI.pdf. Accessed March 25, 2013.
2. Ovarian function in amenorrheic and menstruating users of a levonorgestrel-releasing intrauterine device;Nilsson;Fertil Steril,1984
3. Scholten PC. Thesis. The Levonorgestrel IUD: clinical performance and impact on menstruation. Utrecht: University Hospital, 1989.
4. Pharmacokinetic and pharmacodynamic studies of levonorgestrel-releasing intrauterine device;Xiao;Contraception,1990
5. Population Council. Jadelle (levonorgestrel implant) prescribing information. 2002. Available at: http://www.accessdata.fda.gov/drugsatfda_docs/label/2002/20544se2-003_jadelle_lbl.pdf. Accessed February 8, 2013.