Veja PaperScope .
PaperScope is a tool for graphically exploring the Astrophysics Data System (ADS) which is a database of published astrophysics papers (http://adsabs.harvard.edu/). PaperScope is extremely useful for identifying the citation/reference relationships between papers, and enables the user to visualize these relationships to make locating papers of interest easier. Use it for constructing reference or citation chains, as well as identifying common references/citations between several key papers. It is a tool designed to simplify the process of searching for relevant papers to an astrophysics researcher whether they be a professor, post doc, or student.