Zotero - Zotero is a free, easy-to-use tool to help you collect, organize, cite, and share research.
Mendeley - Easily organize your papers, read & annotate your PDFs, collaborate in private or open groups, and securely access your research from everywhere.
EndNote - Accelerate Your Research. Save time, stay organized, collaborate with colleagues and get published with EndNote 20.
EasyBib - Automatic works cited and bibliography formatting for MLA, APA and Chicago/Turabian citation styles.
JabRef - Graphical Java application for managing bibtex (. bib) databases.JabRef · JabRef Help · JabRef | Blog · OpenOffice/LibreOffice .
BibGuru - BibGuru is a bibliography and citation generator for students.