A method (and structure) of querying one or more Web-based data sources, includes receiving a compound query statement having at least one first-level query and at least one aggregation operator. An aggregation operator is determined which applies to each first-level query. Each aggregation operator...http://www.google.co.uk/patents/US20030187841?utm_source=gb-gplus-sharePatent US20030187841 - Method and structure for federated web service discovery search over multiple registries with result aggregation
