Comfort, J. (1996). Effective telephoning. Oxford: Oxford University Press.
Dyfyniad Arddull ChicagoComfort, Jeremy. Effective Telephoning. Oxford: Oxford University Press, 1996.
Dyfyniad MLAComfort, Jeremy. Effective Telephoning. Oxford: Oxford University Press, 1996.
Rhybudd: Mae'n bosib nad yw'r dyfyniadau hyn bob amser yn 100% cywir.