Open Access

A browser extension, easy to install and use. Just add the extension from their website, and a black padlock will appear on your browser. If an OA version of the article you browse is available, the padlock will turn green, and when you click on it it will redirect you to OA version of the article.

A free plugin that enables you to access full-text PDFs in one click. If there is an OA version of the research paper or article, Kopernio will find it and enable the user to access it with one click.