1. A method performed by a system comprising one or more computers, the method comprising: determining that a first search query includes a respective text reference to each of one or more predetermined attributes, wherein each attribute is associated with a first entity type; for each of a plurality of entities of the first entity type, generating a combined search query that includes the first search query and a name of the entity; obtaining search results from a search engine for each of the plurality of entities using the combined search query for each respective entity; and using the obtained search results to generate combined search results to include in a response to the first search query, wherein using the obtained search results to generate combined search results comprises: generating a respective combined score for each of a plurality of resources identified by the obtained search results, wherein the respective combined score for each resource is a combination of scores associated with obtained search results identifying the resource, and wherein generating the respective combined score for each of the resources comprises: identifying a plurality of search results identifying the resource, wherein each search result identifying the resource is obtained from the search engine in response to a respective combined query, and wherein each search result identifying the resource is associated with a respective first score, and generating the combined score for the resource by combining the first scores associated with the search results identifying the resource; and ranking the obtained search results based on the combined scores for the respective resources identified by each search result.