1. Alex Catalogue of electronics Texts
3. AMS (American Mathematical Society) Books
4. Authorama Public Domain Books
5. Bibliomania
6. Bookboon
7. Bookyards
8. CABI
9. DE GRUYTER
10. Digital Library of India (DLI)
11. Directory of Open Access Books (DOAB)
12. E-Book Lobby
14. Free Book Spot
19. Get Free eBooks
20. Google Books
21. HathiTrust Digital Library
22. Intech
23. Internet Archive
24. JSTOR
28. M Library
29. ManyBooks
30. McGill Library (Open & Free Resources)
32. National Digital Library of India (NDL)
33. Northcentral University Library
34. Notre Dame De Namur University
35. O’REILLY
36. OAPEN
39. Open Access to ACM Digital Library
40. Open Knowledge Repository - World Bank
41. Open Library
44. PDF Drive
47. Public Library of Science-PLOS
48. Rare Book Room
49. ReadPrint
52. World Library Foundation Branches and Portals
53. ZSR Library