1. Carcinoma of the anal canal;Ryan;N Eng J Med,2000
2. Cancer incidence in Canada 2004 to 2005;Statistics Canada,2007
3. SEER cancer statistics review, 1975-2003;Ries,2005
4. Tumours of the anal canal;Fenger,2000
5. Anal cancer: an overview;Uronis;Oncologist,2007