CiteULike CiteULike is a free service to help you to store, organize and share the scholarly papers you are reading. When you see a paper on the web that interests you, you can click one button and have it added to your personal library. CiteULike automatically extracts the citation details, so there's no need to type them in yourself. It all works from within your web browser so there's no need to install any software. Because your library is stored on the server, you can access it from any computer with an Internet connection.

Connotea Director of Open Access Journals - The aim of the Directory of Open Access Journals is to increase the visibility and ease of use of open access scientific and scholarly journals thereby promoting their increased usage and impact. The Directory aims to be comprehensive and cover all open access scientific and scholarly journals that use a quality control system to guarantee the content.

Mendeley - 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 is a free, easy to use tool to help you collect, organize, cite, and share your research sources.