5. A system for displaying an entry in a citation index for a cited document cited in a plurality of citing documents, each respective citing document comprising text and at least one citation to the cited document, the system comprising: a programmable processor, a memory coupled to the processor, a computer-readable storage medium, an input device, and an electronic display device; the memory storing instructions that, when executed by the processor, cause the system to carry out a method that comprises retrieving from a computer-readable storage medium enclosing text from a selected one of the citing documents, the enclosing text including (a) a first textual portion that immediately precedes a selected one of the citations in the selected citing document, (b) the selected citation in the selected citing document, and (c) a second textual portion that immediately follows the selected citation in the selected citing document; and causing an electronic display device to display the entry, display of the entry comprising simultaneously displaying information that identifies the cited document, information that identifies individually each of a plurality of the citing documents that includes the selected citing document, and the enclosing text, the enclosing text being displayed adjacent to the information that identifies the selected citing document but apart from the information that identifies the cited document.
6. The system of claim 5 , wherein the method comprises, in response to a first input provided by a user through an input device, causing the electronic display device to stop displaying the enclosing text while continuing to display the information that identifies the plurality of the citing documents.