Gilbert, J. B. (2005). Clear speech: Pronunciation and Listening Comprehension in North American English (Tercera Edición.). Cambridge University Press.
Dyfyniad Arddull ChicagoGilbert, Judy B. Clear Speech: Pronunciation and Listening Comprehension in North American English. Tercera Edición. Cambridge: Cambridge University Press, 2005.
Dyfyniad MLAGilbert, Judy B. Clear Speech: Pronunciation and Listening Comprehension in North American English. Tercera Edición. Cambridge University Press, 2005.
Rhybudd: Mae'n bosib nad yw'r dyfyniadau hyn bob amser yn 100% cywir.