Useful Book Links

Books on programming:
https://github.com/EbookFoundation/free-programming-books/blob/master/free-programming-books.md
https://github.com/bjut-hz/E-Books
https://github.com/sivaprak/myBooks
https://github.com/sanigo/books
O'Reilly Free Books:
https://gist.github.com/viruscmd/5960adf1e5b5cf1e3d465dd3ad9e1aa8
https://gist.github.com/abstractart/7b969dd9004cd11e04ba0a031fa4ab6c
Togaf Books
https://github.com/pankajchopra/togaf
Blockchain Books:
https://github.com/ShubhamTatvamasi/blockchainbooks
Books on Hadoop/Big Data
https://github.com/TechBookHunter/Free-Hadoop-Books/tree/master/book