Mendeley

Mendeley helps organize your references to information sources so you can cite as you write up your research work. It also helps search, annotate, sort your documents, and share efficiently.

– Mendeley can be installed on your computer, as a plug-in to word processing software, or accessed online.
 

Zotero

Zotero is free, open-source software that collects, manages, and cites research sources, including online journal articles, books from the library catalog, news articles, and websites. It's a great time-saving tool that helps you avoid writing citations and bibliographies manually.