National Archive of India
https://www.abhilekh-patal.in/
E Books from Indian Academy of Sciences
https://www.ias.ac.in/Publications/e-Books/
Department of Electronics and Communication Engineering, DUIET
https://sites.google.com/view/ocwduietece/
Links suggested by AICTE
Other Links
SWAYAM Online Courses: http://storage.googleapis.com/uniquecourses/online.html
UG/PG MOOCS: http://ugcmoocs.inflibnet.ac.in/ugcmoocs/moocs_courses.php
E-Content Courseware for UG: http://cec.nic.in/cec/
CEC-UGC Youtube Channel: https://www.youtube.com/user/cecedusat
National Digital Library : https://ndl.iitkgp.ac.in/