E-Books
https://www.pdfdrive.com
http://read.gov
https://about.jstor.org/covid19/expanded-access-to-ebooks
https://bookboon.com
http://www.esahity.com/
https://www.oercommons.org/hubs/open-textbooks
https://storylineonline.net/
Other resources
http://www.worldebooklibrary.org/
https://www.khanacademy.org
https://archive.org/
https://ndl.iitkgp.ac.in
https://nptel.ac.in/
https://swayamprabha.gov.in/
http://egyankosh.ac.in
https://swayam.gov.in/
http://epgp.inflibnet.ac.in/
https://www.hindawi.com/
https://www.doaj.org/
MPSC Preparation websites
https://www.freeonlinetest.in/
https://www.mpsc.gov.in/
https://missionmpsc.com/
https://www.gkduniya.com/
Reference Management software
https://www.zotero.org/
https://www.mendeley.com/