The paper analyzes 60 documents about the 4Ps of marketing mix in libraries in Information Science literature from 1975 to 1995, in order to know the writers and how many have written about the topic. It also asks such questions as: Who was the pioneer? Who was the pioneer to add Ps? It shows a chronology of the reviewed documents and it comments on the 4Ps, and suggests the adoption of the most completed addition proposal presented in order to guarantee library future.
marketing mix; information agencies