Please check the following researchgate link.

https://www.researchgate.net/publication/221732951_Origins_of_HIV_and_the_AIDS_pandemic

Article Origins of HIV and the AIDS pandemic

Please have a look at this link and PDF attachments also.

https://www.yumpu.com/en/document/view/51114852/origins-of-hiv-and-the-evolution-of-resistance-to-aids-researchgate

Please have a look at this link also.

https://googleweblight.com/i?u=https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2935100/&grqid=FxjjIq3Q&hl=en-IN

Kindly check here..

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2935100/

See here too...

http://evolution.berkeley.edu/evolibrary/article/medicine_04

More info...

https://www.avert.org/professionals/history-hiv-aids/origin

More to explore..

http://www.theaidsinstitute.org/node/259

To be seen..

http://www.dnadarwin.org/casestudies/7/FILES/HIVSG1.2.pdf

Also to explore...

https://en.wikipedia.org/wiki/History_of_HIV/AIDS

See here too..

http://www.nature.com/nrg/journal/v5/n1/full/nrg1246.html

Should also be seen..

http://www.healthline.com/health/hiv-aids/evolution-of-hiv-treatments

Thanks you all.