1. A computer-implemented method comprising: extracting a topic from a digital text document, wherein the extracting includes identifying a first additional term in the digital text document that co-occurs with the topic; obtaining a plurality of concepts; automatically generating a first query that includes the topic and the first additional term; determining coherency of the first query by mapping the first additional term to the plurality of concepts; in response to determining that the first query is not coherent, identifying a second additional term in the digital text document that co-occurs with the topic; automatically generating a second query that includes the topic, the first additional term, and the second additional term; identifying a plurality of candidate videos from a video source, wherein the plurality of candidate videos are identified in response to the second query; selecting a video from the plurality of candidate videos for the extracted topic based on a relationship between the extracted topic and the plurality of concepts, and based on relationships between the plurality of concepts and the plurality of candidate videos; and associating the selected video with the extracted topic.