Information retrieval consists of four main stages: Identifying the exact subject of the search; Locating this subject in a guide which refers the searcher to one or more documents; Locating the documents; Locating the required information in the documents.

p. 6 ; As cited in: Mei Hong (2006) "Potential Usage of Faceted Classification in Internet ''Information Retrieval''" Interdisciplinary Information Sciences, Vol. 12, No. 1, p. 51 - Classification and indexing in the social sciences (1963)