1. Coffin, J. M. Molecular biology of HIV. In The Evolution of HIV, ed. K. A. Crandall, 1999; 3-40.
2. https://aidsinfo.nih.gov/understanding- hiv-aids/factsheets/19/45/hiv-aids--the- basics
3. https://www.britannica.com/science/AIDS/Theorigin-of-HIV
4. https://www.alamy.com/stock-photo/immunodeficiency.html?sortBy=relevant
5. https://micro.magnet.fsu.edu/cells/virus/hivvirus.html