Without recommending any chemical bibliocides, helps librarians improve their collection by systematically weeding out volumes. Summarizes opinion, experience, and research on the matter, and also serves as a guide for librarians and a textbook for a librarianship course. The fourth edition has itself been weeded to simplify some discussions and reduce the quantity of less useful material; the only previous dates noted are 1982 and 1989. Annotation c. by Book News, Inc., Portland, Or.