16. A method comprising: identifying a first set of documents from a first database using a query for legal information; automatically identifying metadata associated with one or more of the identified first set of documents by executing the query against a plurality of additional databases comprising at least a legal classification code database, a legal headnotes database, and a secondary legal documents database; automatically identifying, based on the identified metadata, a set of key classification codes associated with the metadata and the identified first set of documents; automatically identifying a second set of two or more documents based on the metadata associated with one or more of the identified first set of documents and the identified set of key classification codes; automatically ranking the second set of documents based at least in part on identification of the second set of documents; and automatically outputting a list of one or more of the ranked documents to a client access device.
16. A method comprising: identifying a first set of documents from a first database using a query for legal information; automatically identifying metadata associated with one or more of the identified first set of documents by executing the query against a plurality of additional databases comprising at least a legal classification code database, a legal headnotes database, and a secondary legal documents database; automatically identifying, based on the identified metadata, a set of key classification codes associated with the metadata and the identified first set of documents; automatically identifying a second set of two or more documents based on the metadata associated with one or more of the identified first set of documents and the identified set of key classification codes; automatically ranking the second set of documents based at least in part on identification of the second set of documents; and automatically outputting a list of one or more of the ranked documents to a client access device. 17. The method of claim 16 , wherein the ranking the second set of documents includes using a learning machine to process a set of feature vectors including one or more features from the group consisting of: a feature based on text similarity; a feature based on number of shared legal classification codes; and a feature based on number of shared legal citations.