Short introduction to Vector Space Model (VSM) In information retrieval or text mining, the term frequency - inverse document frequency also called tf-idf, is
O. Alonso, J. Strötgen, R. Baeza-Yates, и M. Gertz. Proceedings of the 1st International Temporal Web Analytics Workshop, том 707 из CEUR Workshop Proceedings, стр. 1-8. CEUR-WS.org, (2011)