Beatty, J., & Drucker, P. F. (1998). The world according to Peter Drucker. Universities Press.
Dyfyniad Arddull ChicagoBeatty, Jack, and Peter F. Drucker. The World According to Peter Drucker. New York ; india: Universities Press, 1998.
Dyfyniad MLABeatty, Jack, and Peter F. Drucker. The World According to Peter Drucker. Universities Press, 1998.
Rhybudd: Mae'n bosib nad yw'r dyfyniadau hyn bob amser yn 100% cywir.