BMC publishes around 200 open access journals related mainly to medicine and biology.
Brill is an international academic publisher that specialises in humanities, social sciences, law and ecclesiology. Brill has got both journals and books under its open access collection. Limit your your results to OA by selecting free as well as open access content under the filter 'access' provided on the left hand side of the page
Cambridge Core(external link)
All the academic content of Cambridge University Press is available from this link. Though everything is not freely downloadable, CUP provides access to both its journals and books. Users can make a free account in the site and have the option to filter their results just to freely accessible ones. All Cambridge Core resources are not immediately listed in academic search engines. A list of open access journals and books of CUP is available from this page(external link).
De Gruyter Open(external link)
In the general search page of De Gruyter, select all 'available content' under the heading 'access' to avail open access resources ranging from books to book chapters to journal articles. De Gruyter publishes around 100 open access journals(external link).
Elsevier Open(external link)
Provides access to all open access journals published by Elsevier. Users can search the collection using key words, subject terms and journal title.
Frontiers is one of the world’s leading open access publishers. Frontiers, which publishes more than 180 journals, features at the top five most cited journal publishers. Users can make journal level as well as article level search, which could be further searched subject wise. Though most Frontiers journals are included in open access journal aggregators like DOAJ, many new journals are not featured. This link(external link), which provides a full list of frontier journals, also facilitates keyword search for articles(external link).
Intech Open(external link)
Intech Open publishes peer reviewed open access books by subject fields ranging from physical sciences to humanities.
JSTOR Open(external link)
Open source content from JSTOR, including journal articles, books, and research reports, can be accessed. Resources from South Asia Open Archives(external link), a curated collection of key historical and contemporary sources in arts, humanities and social sciences, from and about South Asia, could also be accessed from JSTOR open.
MDPI is one of the pioneers in open access publishing that has around 370 journals in its collection. Though many of its journals feature on open access journal aggregators like DOAJ, this portal facilitates extensive search through the full portfolio of its journals.
MIT open(external link)
Access to books and journals published by Massachusetts Institute of Technology. As many of these journals are hybrid ones, not fully open access, it is good to search using MIT journals(external link) link, which provides search filters for open access and free ones.
National Academic Press Open(external link)
The National Academies Press (NAP) publishes the reports of the National Academies of Sciences, Engineering, and Medicine of USA, and provides free access to more than 10,000 books.
Oxford University Press(external link)
Provides access to all open access resources available with Oxford University Press. Oxford university follows a graded access policy regarding its open resources. While most of its new journals are published under open access, older ones are not providing all their articles free.
Project Muse Open(external link)
Books and journals freely accessible through Project Muse are accessible in this link. Most of these titles are not listed in open access databases like DOAJ that compiles resources from open access sources.
Public Library of Science(external link)
Public library of Science, which is one of the leading open access publishing houses, provide a search interface to search all their journal articles using key words. Please click on the edit query to start with a search or use the search field on the top left-hand side of the page. Advanced search interface provides dropdown menus to limit the search to title, abstract, author and other limiters. The list of PLOS journals is available from this link(external link).
Sage Journals(external link)
A search interface to cover journal content from Sage. Use the limiter ‘open access’ on the lower left hand side of the results page to get only OA journal content. A list of fully open access journals from Sage is accessible here(external link).
Springer (external link)
Provides a search interface to access all open access journal articles, books and other documents published under different Springer imprints. While using advanced search, one needs to untick ‘include preview only content’ box, which is at the lower left-hand side of the page, to get only OA documents. For accessing only eBooks, use this link(external link). Though academic search engines list springer journal results, books are not always accessible.
A list of open access journals from different imprints of springer is available from Springer Open(external link) and Springer Nature(external link).
Taylor and Francis Open(external link)
Allows access to all online content available through imprints of Taylor and Francis group, such as Routledge, Dove Press, Cogent OA, F1000Research. A search interface to search all their OA content is available with advanced search functionalities. Their OA eBooks (external link)are available from here.(external link)