Open Access

Open Access Journals - Pepperdine Digital Commons 

Undergraduate Student Research - Pepperdine Digital Commons 

Overview of Pepperdine Digital Commons 

Pepperdine Digital Commons FAQs

Digital Public Library of America
Directory of Open Access Books
HathiTrust
​JSTOR Open Access Books
Luminos (UC Press)
National Academies Press
Open Humanities Press
Open Library (Internet Archive)
Open Research Library
Open Textbook Library
Project MUSE Open Access Books

Humanities
CORE (COnnecting REpositories)
DOAJ - Directory of Open Access Journals
Digital Humanities Now
DPLA
JURN
Open Access Publishing in European Networks (OAPEN)
Open Library of Humanities

Religion

CORE (COnnecting REpositories)
Open Access Digital Theological Library

Social Sciences
Cogprints
CORE (COnnecting REpositories)
​DOAJ - Directory of Open Access Journals
PsyArXiv - free preprint service for the psychological sciences
SSOAR - Social Science Open Access Repository
SSRN - Social Science Research Network
SocArXiv (Under Development)

Sciences
DOAJ - Directory of Open Access Journals
CORE (COnnecting REpositories)
arXiv
BioMed Central​
Chemistry Central
ChemRxiv
​PeerJ
Project Euclid
PLoS 
PubMed 
SAO/NASA Astrophysics Data System

Conservation of cultural heritage:

Conservation Journals (list from The Getty Conservation Institute)

Find more at OpenDOAR and ROAR.

Cambridge Journals OA Content

Oxford Press OA Journals

​Elsevier OA ("Open Science")

​SAGE OA ("Gold Open Access Journals")

Springer OA ("Springer Open")

Taylor & Francis OA ("Open Journals")

Wiley OA ("OnlineOpen", hybrid OA)

Open Data:
Data.gov
Los Angeles Open Data - City of Los Angeles
Open Data Network
Google Public Data

ROARMAP, the Registry of Open Access Repository Mandates and Policy, is a registry of open access mandates and policies adopted by universities, research institutions, and research funders.