Preston, D. R., & Roger W. Shuy. (1988). Varieties of American English: Teacher's handbook. D.C.: U.S. Information Agency.
Dyfyniad Arddull ChicagoPreston, Dennis R., và Roger W. Shuy. Varieties of American English: Teacher's Handbook. D.C.: U.S. Information Agency, 1988.
Dyfyniad MLAPreston, Dennis R., và Roger W. Shuy. Varieties of American English: Teacher's Handbook. D.C.: U.S. Information Agency, 1988.
Rhybudd: Mae'n bosib nad yw'r dyfyniadau hyn bob amser yn 100% cywir.