Baeza-Yates, Ricardo ; Calderón-Benavides, Liliana ; González-Caro, Cristina: The Intention Behind Web Queries. In: String Processing and Information Retrieval (2006), S. 98--109

Rose, Daniel E. ; Levinson, Danny: Understanding user goals in web search. In: Proceedings of the 13th international conference on World Wide Web. New York, NY, USA : ACM, 2004 (WWW '04). - ISBN 1-58113-844-X, S. 13--19