National Digital Library of India https://ndl.iitkgp.ac.in/

Directory of Open Access Repositories http://www.opendoar.org/find.php

Internet Archive https://archive.org/details/texts

Open Library https://openlibrary.org/

Standard EBooks https://standardebooks.org/

Springer Open Access Books https://www.springer.com/gp/open-access/books

AICTE Books https://www.aicte-india.org/

DOAB (Directory of Open Access Books) https://www.doabooks.org/

FreeComputerBook.com https://freecomputerbooks.com/

Shodganga: a reservoir of Indian Theseshttps://shodhganga.inflibnet.ac.in/

Open access theses and dissertations https://oatd.org/

E Pustakalaya (Hindi Books) https://epustakalay.com/

E Sahitya (Marathi Books) https://www.esahity.com/