Zotero is a free citation manager available from http://zotero.org, and it exists as a desktop version, an online version, and a browser extension. It's great at collecting citation information from webpages as well as from databases, and you can create groups to share citations with others. It also has a plug-in that allows you to cite sources in MS Word, LibreOffice, and Google Docs.
If you have a list of references in a document and would like to get them into Zotero, you can use AnyStyle.io to convert the references into a file that can be imported into Zotero. Just follow the directions on the site and save the references to BibTeX format. Download the file, and then in Zotero, go to File -- Import -- A file (BibTeX, RIS, Zotero RDF, etc.). Select the file from your downloads and click Open. The reference will be added to your Zotero library. Remember to check over the references after they've been added to Zotero to make sure they're correct.
Need help working with Zotero? Contact email@example.com for help at Newman Library. Please included a detailed description of the problem you're experiencing, as well as any screenshots of the error. You can also sign up for a virtual consultation here (select Citation Managers from the list of topics).
For additional videos, visit https://www.zotero.org/support/.