APA
Koontz & Weinrich, . (1990). Essentials of management. New York: McGraw-Hill.
Chicago
Koontz & Weinrich, . 1990. Essentials of management. New York: McGraw-Hill.
Harvard
Koontz & Weinrich, . (1990). Essentials of management. New York: McGraw-Hill.
MLA
Koontz & Weinrich, . Essentials of management. New York: McGraw-Hill. 1990.