Most of the databases on the Search for Articles tab link to the full text of freely available online articles. Many of these are "Open Access."
Open access usually refers to scientific and scholarly research that is freely available online, and users may read, download, copy, distribute, print, search, or link to the full text of these articles, crawl them for indexing, pass them as data to software, or use them for any other lawful purpose, without financial, legal, or technical barriers. Not all journal articles that are freely available online are open access, however.
Try the below listed resources for online journal access. Several also include online books.