1. National Medical Commission

2. Tamilnadu Medical Council

3. World Health Organization(WHO)

4. The American College of Surgeons

5. The Royal College of Surgeons of England

6. Royal College of Surgeons in Ireland

7. Centers for Disease Control and Prevention (CDC)

8. Mayo Clinic

9. WebMD

10. MedlinePlus

11. National Institutes of Health (NIH)

12. The American Heart Association

13. The American Cancer Society