APA

Drucker Peter F,, . (2001). The esential drucker : The best of sixty years of Peter Drucker's essential writings on management. New York: Harper Collins Publishers.

Chicago

Drucker Peter F,, . 2001. The esential drucker : The best of sixty years of Peter Drucker's essential writings on management. New York: Harper Collins Publishers.

Harvard

Drucker Peter F,, . (2001). The esential drucker : The best of sixty years of Peter Drucker's essential writings on management. New York: Harper Collins Publishers.

MLA

Drucker Peter F,, . The esential drucker : The best of sixty years of Peter Drucker's essential writings on management. New York: Harper Collins Publishers. 2001.