OER (Open Educational resouces)

CiteSeerX
InfoPort
World Digital Library
Project Gutenberg
Internet Archive
ScienceDirect
Shodhganga-a reservoir of Indian theses
Directory of Open Access Books (DOAB) CiteSeerX
Directory of Open Access Journals (DOAJ)
Taylor & Francis Open Access
Springer Open
INTECH
e-PG Pathsala
NCERT
NPTEL
SWAYAM Online Courses
National Digital Library of India