11. A system comprising: one or more server devices to: identify a plurality of geographically relevant strings in the document; retrieve a plurality of histograms respectively associated with the plurality of identified strings, each histogram relating occurrences of a particular identified string to geographic regions; combine the plurality of histograms associated with the plurality of identified strings to obtain a combined histogram for the document; and associate a particular geographic region with the document based on the combined histogram.
11. A system comprising: one or more server devices to: identify a plurality of geographically relevant strings in the document; retrieve a plurality of histograms respectively associated with the plurality of identified strings, each histogram relating occurrences of a particular identified string to geographic regions; combine the plurality of histograms associated with the plurality of identified strings to obtain a combined histogram for the document; and associate a particular geographic region with the document based on the combined histogram. 20. The system of claim 11 , where, when associating the particular geographic region with the document, the one or more server devices are further to: analyze the combined histogram for peaks; select a highest peak of the combined histogram; and identify a geographic region corresponding to the highest peak as the particular geographic region.