Quick Cite, which costs 99 cents and is available for both iPhones and Android-based phones, uses the camera on a smartphone to scan the bar code on the back of a book. It then e-mails you a bibliography-ready citation in one of four popular styles—APA, MLA, Chicago, or IEEE.
Mendeley is a free reference manager and academic social network that can help you organize your research, collaborate with others online, and discover the latest research
Zotero [zoh-TAIR-oh] is a free, easy-to-use tool to help you collect, organize, cite, and share your research sources. It lives right where you do your work—in the web browser itself