Duckworth, W. E. A guide to operational research / W. E. Duckworth, A. E. Gear, A. G. Lockett. - 3rd ed. - London : New York : Chapman and Hall, Wiley, 1977. - ix, 205 p. : ill. ; 25 cm. "A Halsted Press book.". Includes bibliographical references and indexes. ISBN: 0470991453 LCCN: 77004247 Subjects--Topical Terms: Operations research Dewey Class. No.: 658.4034