The exemplary embodiments of the present invention provide a system, method and computer program products for determining a particular document that initiated a topic of interest in a collection of documents, were each of the documents has contents and a time it was created. The method includes ranking the documents in the collection based on the respective times that the documents were created, ranking the documents based on how similar their respective contents are to the topic of interest and ranking the documents based on originality of their respective contents. The method further includes producing a composite ranking of the documents based on the time, contents, and originality rankings, and then determining the particular document that initiated the topic of interest from the composite ranking.