Phelps, Rachel (June 2014). "Choosing a Birth Control Method". Association of Reproductive Health Professionals. Bayer Healthcare Pharmaceuticals, Conceptus, Inc. , and Teva Pharmaceuticals. Archived from the original on 2 January 2018. Retrieved September 16, 2016.
doi.org
Mulders, Titia (May 2001). "Use of the novel combined contraceptive vaginal ring NuvaRing for ovulation inhibition". Fertility and Sterility. 75 (5): 865–870. doi:10.1016/S0015-0282(01)01689-2. PMID11334895.
nih.gov
pubmed.ncbi.nlm.nih.gov
Mulders, Titia (May 2001). "Use of the novel combined contraceptive vaginal ring NuvaRing for ovulation inhibition". Fertility and Sterility. 75 (5): 865–870. doi:10.1016/S0015-0282(01)01689-2. PMID11334895.
Phelps, Rachel (June 2014). "Choosing a Birth Control Method". Association of Reproductive Health Professionals. Bayer Healthcare Pharmaceuticals, Conceptus, Inc. , and Teva Pharmaceuticals. Archived from the original on 2 January 2018. Retrieved September 16, 2016.