Gaya APA

DRUCKER, P, F. (2001). Essential drucker: in one volume the best of sixty years of Peter Drucker's (The) . New York: HarperCollins.

Gaya MLA

DRUCKER, Peter, F.. "Essential drucker: in one volume the best of sixty years of Peter Drucker's (The)". New York: HarperCollins, 2001. Text.