Ries, Al ; Trout, Jack The 22 immutable laws of marketing : violate them at your own risk / Al Ries and Jack Trout - 1st ed. - New York Harper 1994 - 143 p. : ill. ; 20 cm. Includes index ISBN: 9780887306662 Subjects--Topical Terms: Marketing Management Dewey Class. No.: 658.8 / RIE