Hi friends,
I am posting this on behalf of Ankur Kaushik. Ankur has one of highest score in GS-2 (124). His IR notes maybe helpful to you.
About Ankur Kaushik: Ankur is NSIT 2015 pass out in computer science engineering, IRTS from CSE 16 and AIR 37 in CSE 18, a budding poet and author (Check his book: Of Lilies and Graves https://www.amazon.in/Lilies-Graves-Ankur-Kaushik-ebook/dp/B07L14WLJ9)