Tu X, Lou C, Gao E, and Shah IH. (2008) Long-term effects of community-based program of contraceptive use among sexually active youth in Shanghai, China. Journal of Adolescent Health, 42:249-258

Ozumba BC, Obi SN, and ljioma NN. (2005) Knowledge, attitude and practice of modern contraception among single women in a rural and urban community in southeast Nigeria. Journal of Obstetrics and Gynecology, 25(3):292-295

In Focus. Emergency Contraceptive Pills: An Important Option for Young Adults. Pathfinder International. http://www2.pathfinder.org/pf/pubs/focus/IN%20FOCUS/emcon%20final.htmlI. accessed 22 February 2014