HBR. (2006). Harvard business review. Harvard business school.
Dyfyniad Arddull ChicagoHBR. Harvard Business Review. Boston: Harvard business school, 2006.
Dyfyniad MLAHBR. Harvard Business Review. Harvard business school, 2006.
Rhybudd: Mae'n bosib nad yw'r dyfyniadau hyn bob amser yn 100% cywir.