Zotero is a free research tool that helps you gather and organize sources, including: citations, full texts, web pages, images, and other objects. Zotero allows you to share the results of your research in a variety of ways.
Installing a Zotero word processor plugin adds a Zotero toolbar to your word processor (in Word 2008 for Mac the script menu is used; in Word 2010, the Zotero toolbar is in the “Add-Ins” tab on the ribbon).
Drag N Drop
Zotero can be used with Google Docs with drag n drop feature.
Use Zotero's keyboard shortcuts to add citations and bibliographies to Google Docs.
Adding a Citation: To add an in text citation, highlight the reference in Zotero, and press Ctrl+Shift+A (Cmd+Shift+A on a Mac). Paste into Google Docs using Ctrl+V (Cmd+V on Mac) or right click and select paste.
Adding a Bibliography: To create a bibliography, highlight all the references in Zotero using Ctrl+Click (Cmd+Click on a Mac) to select multiple references, then press Ctrl+Shift+C (Cmd+Shift+C on a Mac). Paste into Google Docs using Ctrl+V (Cmd+V on Mac) or right click and select paste.