G. Brajnik, S. Mizzaro, и C. Tasso. SIGIR '96: Proceedings of the 19th annual international ACM SIGIR conference on Research and development in information retrieval, стр. 128--136. New York, NY, USA, ACM, (1996)
K. Järvelin. Proceedings of the 2nd International Conference on the Theory of Information Retrieval. Lecture Notes in Computer Science, 5766, стр. 289-296. Heidelberg, Springer, (2009)