EndNote Web is a bibliographic management tool that offers sophisticated editing capabilities to prepare professional publications, dissertations, and theses. Of course it also manages citations, abstracts, and other elements of resource information.
Zotero is a free/mium, open source reference management application. Zotero allows you to easily save articles found in library subscription databases such as Worldwide Political Science Abstracts, JSTOR, and PubMed, as well as bibliographic details, PDFs or other files, comments/notes, and indexing terms. Most saved PDFs are searchable. Zotero also captures bibliographic information and live screenshots for Web content such as webpages, blog posts, newspaper articles, YouTube videos, Amazon books, and images on sites such as Flickr. When you are ready to write, you can use Zotero to integrate your references into your work in many citation styles using MS Word or LibreOffice. References can be backed up and shared between computers and even with other people over the Web.
The dissemination of research and information through the scholarly journal has in recent years become prohibitively expensive. Explore this site to learn more about the costs of Scholarly Communication and new alternatives.
Consult this page for more detailed information about citation analysis (tracing citation patterns to discover new, related, resources; tracing the impact (measured by citation) of individual publications).