Zotero is a free reference management tool at works on Windows, Apple and Linux. It allows you to...
Collect PDFs, files, images, and more for citation.
Create a bibliography and in-text citations in a variety of reference styles (for example,APA, MLA, Chicago) in a Word or OpenOffice document.
Sync feature can keep your bibliography up to date on all computers and additional backup options can be followed.
Create Groups to share citations, notes and tags with colleagues.
There are two operating platforms for Zotero
Zotero for Firefox lets you capture and organize all your research without ever leaving the browser
Zotero Standalone runs as a separate application and plugs into Firefox, Chrome or Opera.
Here are some resources to help you format your papers and works cited pages.