Koontz, Harold. Essentials of Management Harold Koontz, Heinz Weihrich - 5th ed. - New Delhi : McGraw-Hill Publishing Company Limited, c1990. - xxiii, 530p.: ill.; - Schaum's Outline Series in Accounting, Business and Economics. . ISBN: 007035605X Dewey Class. No.: 658.001 / KOO/ESS