1. Siemiński, A.: The potentials of client oriented prefetching. Intelligent technologies for inconsistent knowledge processing. In: Nguyen, N.T. (ed.) Magill: Advanced Knowledge International, cop., pp. 221–238 (2004)
2. Cox, K.: A Unified Approach to Indexing and Retrieval of Information, DOC 94-10/94 Eanff, Albera, pp. 176 -181 (1994)
3. Cox, K.: Searching by Browsing. University of Canberra, Australia. PhD Thesis
4. Sherman, C.: Humans Do It Better:Inside the Open Directory Project, (July 2000), http://www.infotoday.com/online/OL2000/sherman7.html. (2000)
5. Manning, C., Raghavan, P., Schütze, H.: An Introduction to Information Retrieval. Cambridge University Press, Cambridge (2008)