Fells, R. (2010). Effective Negotiation. Cambridge University Press.
Dyfyniad Arddull ChicagoFells, Ray. Effective Negotiation. New Delhi: Cambridge University Press, 2010.
Dyfyniad MLAFells, Ray. Effective Negotiation. Cambridge University Press, 2010.
Rhybudd: Mae'n bosib nad yw'r dyfyniadau hyn bob amser yn 100% cywir.