Abstract: Within the context of a cross-referenced data-base, an initial “base-set” of results to a query is generated using any conventional search engine tool. The base-set is then expanded by adding to it entries referencing entries in the original set or referenced by those entries, in a possibly iterative manner. The resulting collection of entries and references is represented as a mathematical graph or network, amendable to graph theoretic analysis. Connected components within the graph form top-level clusters, and articulation nodes within these clusters are calculated. These articulation nodes serve as both navigational “gateways” and anchors for sub-clusters. Sub-clusters, consisting of the transitive descendants of the articulation nodes, are associated with each articulation node. The articulation nodes themselves then form a graph, which is analyzed further for prominence, and a hierarchy of articulation nodes is calculated.