1. Kew OM, Cochi SL, Jafari H, Wassilak SGF, Mast EE, Ousmane MD, et al. Possible Eradication of Wild Poliovirus Type 3 — Worldwide, 2012. Morb Mortal Wkly Rep [Internet]. 2014 [cited 2015 Sep 16];63:1031–3. Available from: http://www.cdc.gov/mmwr/preview/mmwrhtml/mm6345a4.htm .
2. Apparent Global Interruption of Wild Poliovirus Type 2 Transmission. Morb Mortal Wkly Rep [Internet]. 2001 [cited 2015 Sep 16];50:222–4. Available from: http://www.cdc.gov/mmwr/preview/mmwrhtml/mm5012a2.htm .
3. Global Polio Eradication Initiative: Polio this week; 2 Sept 2015 [Internet]. 2015 [cited 2015 Sep 7]. Available from: https://web.archive.org/web/20150907180505/http://www.polioeradication.org/Dataandmonitoring/Poliothisweek.aspx .
4. World Health Organization. World Health Organization. WHO Removes Nigeria from Polio-Endemic List. 2015. [Internet]. World Health Organization; 2015 [cited 2015 Oct 17]. Available from: https://web.archive.org/web/20151017231408/http://www.who.int/mediacentre/news/releases/2015/nigeria-polio/en/ .
5. Kalkowska DA, Duintjer Tebbens RJ, Thompson KM. The probability of undetected wild poliovirus circulation after apparent global interruption of transmission. Am J Epidemiol [Internet]. 2012 [cited 2015 Aug 14];175:936–49. Available from: http://www.ncbi.nlm.nih.gov/pubmed/22459121 .