1. A computer-implemented method for processing multi-lingual documents in a document database comprising: generating an initial ranking of retrieved multi-lingual documents using an information retrieval system and based upon a user search query; processing a plurality of vocabulary words based upon occurrences thereof in at least some of the retrieved multi-lingual documents; generating respective relevancies of the vocabulary words based on the occurrences thereof and the user search query; and generating a re-ranking of the retrieved multi-lingual documents based on the relevancies of the vocabulary words.