Other citation tools

ACS ChemWorx is a free research management and storage system that combines reference discovery and management, professional networking, group and task management and manuscript preparation.

Colwiz was created by researchers at the University of Oxford and  is a free reference management tool that provides an easy way to find, read, and cite papers for students, academic groups, and researchers.

JabRef is an open source bibliography reference manager. The native file format used by JabRef is BibTeX, the standard LaTeX bibliography format. JabRef runs on the Java VM (version 1.6 or newer) and should work equally well on Windows, Linux and Mac OS X.

Papers can help you search for and download articles to your desktop. (Papers was originally developed for the Mac OS but, is now available for IOS and Windows.) The Stanford University Libraries offer limited support for Papers users, particularly with issues involving connectivity with library-supported resources.  Free trial (for Mac and PC).  Papers app in iTunes store.