• https://arxiv.org/pdf/1802.01040.pdf (TASI Lectures, involved)
• https://www.henryyuen.net/spring2022/projects/adscft.pdf (Basic story)

Lectures by David Tong:

• http://www.damtp.cam.ac.uk/user/tong/gr/gr.pdf (GR)
• https://www.damtp.cam.ac.uk/user/tong/qft/qft.pdf (QFT)
• http://www.damtp.cam.ac.uk/user/tong/string/string.pdf (String Theory)