1. http://globocan.iarc.fr/Pages/fact_sheets_cancer.aspx.
2. http://www.cancer.org/cancer/breastcancer/detailedguide/breast-cancer-key-statistics
3. Global cancer statistics;Jemal;Ca-Cancer J. Clin.,2011
4. http://www.nlm.nih.gov/medlineplus/ency/article/000913.htm