APA
Drucker Peter F, . (2008). Essentials of Drucker The Best of Sixty Years of Peter Drucker's Essential Writings on Management. New York: Harper.
Chicago
Drucker Peter F, . 2008. Essentials of Drucker The Best of Sixty Years of Peter Drucker's Essential Writings on Management. New York: Harper.
Harvard
Drucker Peter F, . (2008). Essentials of Drucker The Best of Sixty Years of Peter Drucker's Essential Writings on Management. New York: Harper.
MLA
Drucker Peter F, . Essentials of Drucker The Best of Sixty Years of Peter Drucker's Essential Writings on Management. New York: Harper. 2008.