Hundreds of Open Access Ebooks covering a variety of subject areas.

Leading publisher of open access scientific content with nearly 400 scholarly journals across all major disciplines. Discover our open access portfolio. De Gruyter is home to around 100 fully open access journals across STEM and HSS disciplines.

IJSRM is a online open access journal that publishes articles in the field of Computer Science, Engineering, medical science, social science, economics, clinical research, mathematics, education, bio science, science, Management & Arts . It is an international journal to encourage research publication to research scholars, academicians, professionals and students engaged in their respective field. The journal also provides an international forum to disseminate their knowledge.

African Journals OnLine (AJOL) is the world's largest and preeminent platform of African-published scholarly journals. AJOL is a Non-Profit Organisation that (since 1998) works to increase global & continental online access, awareness, quality & use of African-published, peer-reviewed research. Millions of monthly downloads by site users from nearly every country in the world are an indication of the need and widespread use of the AJOL initiative. More than half of the repeat users are from Africa.

Hosted by Columbia University Libraries is a collection of internet resources on Africa; the site also hosts a comprehensive portal for United Nations Agencies on Africa, a useful collection of official documentation on institutional development.

The Bielefeld Academic Search Engine (BASE) is operated by the Bielefeld University Library in Germany, and it offers more than 240 million documents from more than 8,000 sources. Sixty percent of its content is OA, and you can filter your search accordingly.

BASE has rigorous inclusion requirements for content providers regarding quality and relevance, and they maintain a list of content providers for the sake of transparency, which can be easily found on their website. BASE has a fairly elegant interface. Search results can be organized by author, title, or date.

From the search results, items can be selected and exported, added to favorites, emailed, and searched in Google Scholar. There are basic and advanced search features, with the advanced search offering numerous options for refining search criteria. There is also a feature on the website that saves recent searches without additional steps from the user.

CORE is a multidisciplinary aggregator of OA research. CORE has the largest collection of OA articles available. It allows users to search more than 219 million OA articles. While most of these link to the full-text article on the original publisher's site, or to a PDF available for download, five million records are hosted directly on CORE.

The Digital Library of the Commons (DLC) is a gateway to the international literature on the commons. The DLC provides free and open access to full-text articles, papers, and dissertations. This site contains an author-submission portal; an Image Database; the Comprehensive Bibliography of the Commons; a Keyword Thesaurus, and links to relevant reference sources on the study of the commons.

DOAB is a community-driven discovery service that indexes and provides access to scholarly, peer-reviewed open access books and helps users to find trusted open access book publishers. All DOAB services are free of charge and all data is freely available.

DOAJ is a community-curated online directory that indexes and provides access to high quality, open access, peer-reviewed journals.

Run by the British Library, the E-Theses Online Service (EThOS) allows you to search over 500,000 doctoral theses in a variety of disciplines. All of the doctoral theses available on EThOS have been awarded by higher education institutions in the United Kingdom.

Although some full texts are behind paywalls, you can limit your search to items available for immediate download, either directly through EThOS or through an institution's website. More than half of the records in the database provide access to full-text theses.

EThOS notes that they do not hold all records for all institutions, but they strive to index as many doctoral theses as possible, and the database is constantly expanding, with approximately 3,000 new records added and 2,000 new full-text theses available every month. The availability of full-text theses is dependent on multiple factors, including their availability in the institutional repository and the level of repository development.

Collection: 500,000+

Other Services: None

Library Genesis (Libgen) is a file-sharing based library website for scholarly journal articles, academic and general-interest books, images, comics, and magazines. Libgen describes itself as a "links aggregator" providing a searchable database of items "collected from publicly available public Internet resources" as well as uploaded "from users"

OATD.org aims to be the best possible resource for finding open access graduate theses and dissertations published around the world. Metadata (information about the theses) comes from over 1100 colleges, universities, and research institutions. OATD currently indexes 6,341,391 theses and dissertations.

OpenDOAR is the quality-assured, global Directory of Open Access Repositories. You can search and browse through thousands of registered repositories based on a range of features, such as location, software or type of material held. Try it out for yourself:

Paperity boasts its status as the "first multidisciplinary aggregator of OA journals and papers." Their focus is on helping you avoid paywalls while connecting you to authoritative research. In addition to providing readers with easy access to thousands of journals, Paperity seeks to help authors reach their audiences and help journals increase their exposure to boost readership.

Paperity has journal articles for every discipline, and the database offers more than a dozen advanced search options, including the length of the paper and the number of authors. There is even an option to include, exclude, or exclusively search gray papers.

Paperity is available for mobile, with both a mobile site and the Paperity Reader, an app that is available for both Android and Apple users. The database is also available on social media. You can interact with Paperity via Twitter and Facebook, and links to their social media are available on their homepage, including their Twitter feed.

Collection: 8,837,396

Other Services: None

Good Source of Peer-Reviewed Articles: Yes

PDF Drive is your search engine for PDF files. As of today,  PDF Drive has 86,082,494 eBooks for you to download for free. No annoying ads, no download limits, enjoy it and don't forget to bookmark and share the love!

Choose among free epub and Kindle eBooks, download them or read them online. You will find the world’s great literature here, with focus on older works for which U.S. copyright has expired. Thousands of volunteers digitized and diligently proofread the eBooks, for you to enjoy.

The ScienceGate goal is to support all scientific and educational communities to facilitate achieving their goals through the best path. The ScienceGate team tries to make this possible by providing and developing several unique services gathered in a web platform.

Functioning as a research and publishing network, ScienceOpen offers OA to more than 74 million articles in all areas of science. Although you do need to register to view the full text of articles, registration is free. The advanced search function is highly detailed, allowing you to find exactly the research you're looking for.

The Berlin- and Boston-based company was founded in 2013 to "facilitate open and public communications between academics and to allow ideas to be judged on their merit, regardless of where they come from." Search results can be exported for easy integration with reference management systems.

You can also bookmark articles for later research. There are extensive networking options, including your Science Open profile, a forum for interacting with other researchers, the ability to track your usage and citations, and an interactive bibliography. Users have the ability to review articles and provide their knowledge and insight within the community.

Collection: 74,560,631

Other Services: None

Good Source of Peer-Reviewed Articles: Yes

Advanced Search Options: Content type, source, author, journal, discipline

An excellent resource for all aspects of international development and public health (not all are free to download, but many are).

The platform provides access to UN-produced materials in digital format free of charge. At the same time it is a major service for the long-term preservation of the Organization’s collective memory incorporating the latest relevant international standards. It is built on open source technology developed by the European Organization for Nuclear Research (CERN).

Zenodo, powered by the European Organization for Nuclear Research (CERN), was launched in 2013. Taking its name from Zenodotus, the first librarian of the ancient library of Alexandria, Zenodo is a tool "built and developed by researchers, to ensure that everyone can join in open science." Zenodo accepts all research from every discipline in any file format.

However, Zenodo also curates uploads and promotes peer-reviewed material that is available through OA. A DOI is assigned to everything that is uploaded to Zenodo, making research easily findable and citable. You can sort by keyword, title, journal, and more and download OA documents directly from the site.

While there are closed access and restricted access items in the database, the vast majority of research is OA material. Search results can be filtered by access type, making it easy to view the free articles available in the database.

Collection: 2,220,000+