DOAJ is a community-curated list of open access journals and aims to be the starting point for all information searches for quality, peer reviewed open access material.
EBSCO Discovery Service indexes a large high-end full text collection of content as well as entire library collections. EBSCO’s resources are available in hundreds of thousands of institutions worldwide.
OCLC WorldCat is an online computer library containing high quality, global
J-Gate is the largest E-journal database containing global content from various
Google Scholar is a freely accessible web search engine that indexes the full text or metadata of scholarly literature across an array of publishing formats and disciplines.
Semantic Scholar is a project developed at the Allen Institute for Artificial Intelligence. Publicly released in November 2015, it is designed to be an AI-backed search engine for scientific journal articles. Semantic Scholar is designed to highlight the most important and influential papers, and to identify the connections between them.
International Scientific Indexing is an indexing service that is committed to
increasing the visibility of high quality open-access research.
Directory of Research Journals Indexing is an indexing database dedicated to
disseminating open-access content.
Scientific Indexing Services is an indexing databases developed by scientists
who are devoted to propagating high quality research.
Research Bib is an indexing database that allows for easy access of journal
articles and research papers.
Cosmos is an indexing database developed by scientists who are devoted to
propagating high quality research.
With a categorized database that covers 39226 open-access titles, Genamics JournalSeek is one of the largest indexation websites.