Heller, Robert, 1932- Stephen Covey : the bestselling teacher of personal and professional effectiveness / Robert Heller. - London : Dorling Kindersley, 2001. - 112p. : ill. ; 21 cm. - Business masterminds . ISBN: 0751312789 40.80 Dhs Subjects--Personal Names: Covey, Stephen. Subjects--Topical Terms: Success--Psychological aspects.Psychologists--United States--Biography.