Academia is not an open access source. But by creating a free account on this academic networking site, users can download scholarly works uploaded on this site.
Though Bielefeld Academic Search Engine mainly deals with bibliographic metadata and not with full text resources, users can get access to full text articles through the links provided. Being a search engine that collocates mainly open access resources, all fully downloadable documents are marked distinctively.
An Academic search engine exclusively for open access content. For all its search results, unlike general academic search engines like Google Scholar, CORE provides links to either PDF resources or full text web pages.
Dimensions is a linked research data platform developed by Digital Science(external link), which also work as an academic search engine. Though Dimension’s free version does not provide all its functionalities, it works as an effective discovery service with citation analysis. Users can limit their results to just open access ones.
Google Scholar(external link)
Google scholar is the most widely used academic search engine with the largest database of academic resources among all search engines.
The lens is a research analytical platform that provides access to patents and scholarly research. As lens is supported with comprehensive citation analytics, evaluation of research output is easier on this platform. In comparison with other search engines, number of search filters are more diverse, and users can filter their results to just open access ones. Above the search box, change from the default 'patents' to 'scholarly works' to get results from research publications.
Though ResearchGate is not an open access initiative, this academic social networking site offers free access to scholarly output and facilitates academic networking. Users can directly ask authors for a copy of their publications.
Semantic Scholar(external link)
This search engine, which uses artificial intelligence-enabled search, claims to return with more relevant results to users’ queries when compared to conventional academic search engines.
X-MOL is an academic search engine with effective filters to limit your results to just title and abstract fields. You can also filter your results to open access titles with full text.