Gaya APA

Drucker, Peter F. (1999). Management challenges fort the 21st century . New York: Harper Collins Publ..

Gaya Chicago

Drucker, Peter F. Management challenges fort the 21st century. New York: Harper Collins Publ., 1999. Buku.

Gaya MLA

Drucker, Peter F. Management challenges fort the 21st century. New York: Harper Collins Publ., 1999. Buku.

Gaya Turabian

Drucker, Peter F. Management challenges fort the 21st century. New York: Harper Collins Publ., 1999. Buku.