Drucker, P. F. (2006). Classic Drucker: Essential wisdom of Peter Drucker from the pages of Harvard Business Review. Boston: Harvard Business Review Book.
Dyfyniad Arddull ChicagoDrucker, Peter F. Classic Drucker: Essential Wisdom of Peter Drucker From the Pages of Harvard Business Review. Boston: Harvard Business Review Book, 2006.
Dyfyniad MLADrucker, Peter F. Classic Drucker: Essential Wisdom of Peter Drucker From the Pages of Harvard Business Review. Boston: Harvard Business Review Book, 2006.
Rhybudd: Mae'n bosib nad yw'r dyfyniadau hyn bob amser yn 100% cywir.