(2003). Negotiation. Harvard business school.
Dyfyniad Arddull ChicagoNegotiation. Boston: Harvard business school, 2003.
Dyfyniad MLANegotiation. Harvard business school, 2003.
Rhybudd: Mae'n bosib nad yw'r dyfyniadau hyn bob amser yn 100% cywir.
(2003). Negotiation. Harvard business school.
Dyfyniad Arddull ChicagoNegotiation. Boston: Harvard business school, 2003.
Dyfyniad MLANegotiation. Harvard business school, 2003.