1. Estimates of the worldwide frequency of twelve major cancers;Parkin;Bull World Health Organ,1984
2. WHO | The global burden of disease: 2004 update [Internet]. WHO. Available at: http://www.who.int/healthinfo/global_burden_disease/2004_report_update/en/. Accessed September 2, 2017.
3. Epidemiological review of head and neck cancers in Karachi;Bhurgri;Asian Pac J Cancer Prev,2006
4. Cancer incidence and mortality worldwide: sources, methods and major patterns in GLOBOCAN 2012: Globocan 2012;Ferlay;Int J Cancer,2015
5. Head and neck cancer: a global perspective on epidemiology and prognosis;Sankaranarayanan;Anticancer Res,1998