Roy J Lewicki. (2001). Essentials of negotiation. Boston, MA: McGraw-Hill.
Dyfyniad Arddull ChicagoRoy J Lewicki. Essentials of Negotiation. Boston, MA: McGraw-Hill, 2001.
Dyfyniad MLARoy J Lewicki. Essentials of Negotiation. Boston, MA: McGraw-Hill, 2001.
Rhybudd: Mae'n bosib nad yw'r dyfyniadau hyn bob amser yn 100% cywir.