Unpaywall, OA Button and CORE Discovery are all Chrome and Firefox extensions that find legal open access copies of individual articles from both publishers and repositories. You can also paste an article DOI (the unique article identifier) into the OA Button and CORE Discovery search bars. Open Access Helper works the same way for iOS and Safari. Test them out with this article: https://doi.org/10.1038/s41559-016-0002 (the article DOI is 10.1038/s41559-016-0002)
LibKey Nomad: part of our BrowZine subscription, LibKey Nomad is a browser extension that integrates with Wikipedia, publisher websites and PubMed to give you easy access to the full text of journal articles. If we do not have a subscription, LibKey Nomad uses data from Unpaywall to search for legal open access copies.
EndNote Click (formerly Kopernio): a Chrome extension that finds articles from our library subscriptions and open access versions.
Google: if you find an article that is behind a paywall, try copy & pasting the article title into a search engine. If there is a copy in a repository it will often display on the first page of search results.
Can’t find what you need? if you can’t find a legal open access version, use our interlibrary loan service and we will source a copy, often within 24 hours. Please do not spend your own money, or grant money, on journal articles. Find out more at https://library.soton.ac.uk/ill.
Articles can be made open access (OA) on the journal website (Publisher OA) or via institutional and subject repositories (green OA, often involving an embargo set by the journal publisher). Find out more about how to make your own work open access at http://library.soton.ac.uk/openaccess/options
Both Scopus and Web of Science have a filter to select only Open Access articles. They predominantly display articles that are gold OA, not the many thousands of articles that are green OA via repositories and preprint servers.
See this helpful blog post from the University of Southampton Digital Learning Team for further suggestions for finding copyright-free images.