1. A method for identifying documents referring to an entity, the entity being associated with a first set of features, the method comprising: identifying a first set of documents based on a first model and the first set of features, wherein the first model includes a first set of rules specifying at least one combination of features from the first set of features that are sufficient for identifying a document referring to the entity, each document of the first set of documents comprising a sufficient number of features in common with the first set of features to identify a document referring to the entity according to the first model; determining a second model based on the features of the first set of documents, wherein the second model includes a second set of rules specifying at least one combination of features from the first set of documents that are sufficient for identifying a document referring to the entity; identifying a second set of documents based on the second model and the first set of features, each document of the second set of documents comprising a sufficient number of features in common with the first set of features to identify a document referring to the entity according to the second model; identifying a second set of features based on the second set of documents; determining if the second set of features are associated with the entity; and responsive to determining that the second set of features are associated with the entity, identifying a third set of documents based on a third model and the second set of features, the third set of documents each comprising a sufficient number of features in common with the second set of features to identify a document referring to the entity according to the third model.