- Academia
- ARIANTA - Polish Scientific and Professional Electronic Journals
- BASE
- CORE
- CrossRef
- Dimensions
- Directory of Research Journals Indexing
- DOAJ (Directory of Open Access Journals)
- EBSCO host
- EconBIZ
- EconPapers
- ERIH PLUS - The European Reference Index for the Humanities and the Social Sciences (2020-10-29)
- EuroPub - Open Access Comprehensive, Multipurpose Database Covering Scholarly Literature
- Fatcat
- GIFT - Global Information Full Text, Switzerland
- Google Scholar
- iDiscover (University of Cambridge)
- Index Copernicus (ICV 2020: 91.17)
- Information Matrix for the Analysis of Journals (MIAR)
- ISSN National Centre
- JournalTOCs - The biggest searchable collection of scholarly journal Tables of Contents (TOCs)
- Korea Open Access platform for Researchers
- LENS
- LIVIVO - interdisciplinary search engine for literature and information in the field of life sciences. It is run by ZB MED – Information Centre for Life Sciences
- Neliti
- OAJI - Open Academic Journals Index is a full-text database of open-access scientific journals
- OpenAIRE
- Open Archives
- Open Ukrainian Citation Index
- Public Knowledge Project
- Publons
- QOAM (Quality Open Access Market)
- RePEc
- ResearchBib
- Research4Life
- ScienceGate Academic Search Engine
- Scilit
- Semantic Scholar (finding articles by Article Title)
- Sherpa Romeo
- SocioRePEc
- Socionet
- UNPAYWALL
- Ulrichsweb™ - Ulrich's Global Serials Directory

Libraries:
- Biblioteka Narodowa (Warsaw)
- Bibliotheks Verbund Bayern (Germany)
- BU Libraries - Boston University Libraries (USA)
- DTU Findit (DTU Library)
- DiscoverEd - The University of Edinburgh (Great Britain)
- Falvey Memorial Library, Villanova University (USA)
- Harvard Library
- Karlsruhe Virtual Catalog (Germany)
- Leibniz Information Centre for Science and Technology and University Library
- LEUPHANA Uni­ver­sität Lüne­burg (Germany)
- Library Hub Discover - combined catalogs of the major UK and Irish libraries
- Monterey Bay Library - California State University (USA)
- Regensburger Katalog (Germany)
- PHSG University of Education St.Gallen
- Stanford University Libraries (USA)
- The Union Catalogue of Serials (ZDB)
- The University of Sheffield (Great Britain)
- The University of Chicago Library (USA)
- University Library of Regensburg
- Universitätsbibliothek Leipzig
- University of Saskatchewan Library (Canada)
- University of Washington Libraries (USA)
- University of South Australia Library
- University of Ottawa Library (Canada)
- University of Toronto Libraries (Canada)
- World Cat
- WILBERT (Wildaüer Bucher +Medien Recherche-Tool)
- York University Libraries (Canada)

Digital archiving:
- PKP Preservation Network (PKP PN)