QUARTETTE (levonorgestrel/ethinyl estradiol and ethinyl estradiol) (Accessed December 27, 2015 from: https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=99c669d8-12ef-4d3a-8761-02d5acb0c8b0
Ethinyl Estradiol/Levonorgestrel. DRUGDEX System. 2015 Truven Health Analytics, Inc. Accessed December 27, 2015 from http://thomsonhc.com.