Zotero is a free, open source, easy-to-use citation management tool that helps you to collect, manage, cite, and share your research sources.
Save citations from databases, websites, and library catalogs.
Users may collaborate with other users using Groups.
Attach PDF's, images, web page snapshots and reading notes to your citations.
Cite sources "in-text" as you write and create reference lists in most styles (e.g., APA, MLA, Chicago, etc.)
Manage, organize and categorize references into collections and sub-collections and by using tags.
Utilize search feature to find your references.
Create a bibliography and export to Word or Google Docs.