00491pamaa2200157 4500 0000023437 20130814090000.0 0894645765 658.4034 ECK T57.6 ECK 1988 ECKER Introduction to operations research Joseph G. Ecker and Michael Kupferschmid. Florida: Krieger Pub. Company, 1991. xvii, 509p.: ill.; 25cm. Includes bibliograaphiacal references and index Operations research