1. A method, comprising: grouping a plurality of electronic documents into a plurality of clusters utilizing a processor of a computing platform to perform a Uniform Resource Locator-based clustering process, wherein said Uniform Resource Locator-based clustering process is based, at least in part, on one or more Uniform Resource Locator attributes for individual electronic documents of the plurality of electronic document; reducing an amount of clusters generated by the Uniform Resource Locator-based clustering process by merging similar clusters based, at least in part, on an expression-based clustering process performed over the plurality of clusters; and providing feedback from the expression-based clustering process to the Uniform Resource Locator-based clustering process to allow refinement of the Uniform Resource Locator-based clustering process to enable additional processing of one or more clusters previously determined by the expression-based clustering process to comprise heterogeneous clusters.