Shurter, R. L., & Nichols, F. G. (1948). Effective letters in business. McGraw-Hill Book Co.
Dyfyniad Arddull ChicagoShurter, Robert L., and Frederick George Nichols. Effective Letters in Business. New York: McGraw-Hill Book Co, 1948.
Dyfyniad MLAShurter, Robert L., and Frederick George Nichols. Effective Letters in Business. McGraw-Hill Book Co, 1948.
Rhybudd: Mae'n bosib nad yw'r dyfyniadau hyn bob amser yn 100% cywir.