(2009). Harvard Business Review 2009. HBR.
Dyfyniad Arddull ChicagoHarvard Business Review 2009. HBR, 2009.
Dyfyniad MLAHarvard Business Review 2009. HBR, 2009.
Rhybudd: Mae'n bosib nad yw'r dyfyniadau hyn bob amser yn 100% cywir.
(2009). Harvard Business Review 2009. HBR.
Dyfyniad Arddull ChicagoHarvard Business Review 2009. HBR, 2009.
Dyfyniad MLAHarvard Business Review 2009. HBR, 2009.