1. A method, comprising: receiving input from a user; executing a search over contents of a data repository responsive to receiving the input from the user, wherein the data repository comprises: first data that identifies a first research document; second data that indicates that a second research document comprises a citation to the first research document; and a sentence in the second research document that includes the citation to the first research document; and based at least in part upon the search, causing a graphical visualization to be presented on a display screen of a computing device of the user, wherein the graphical visualization comprises at least one node that is representative of the first research document, at least one graphical object that visually indicates that the second research document comprises the citation to the first research document, and at least a portion of the sentence in the second research document that includes the citation to the first research document.