19. The system of claim 14 , further configured to perform operations comprising: identifying documents responsive to a query as the first documents; and generating an augmented set of documents responsive to the query by including one or more of the second documents in the first documents.
19. The system of claim 14 , further configured to perform operations comprising: identifying documents responsive to a query as the first documents; and generating an augmented set of documents responsive to the query by including one or more of the second documents in the first documents. 20. The system of claim 19 , further configured to perform operations comprising: receiving the query; and presenting the augmented set of documents in response to the received query.