Dyfyniad APA

Werz, E. W. (1993). The complete customer service letter book. McGraw-Hill.

Dyfyniad Arddull Chicago

Werz, Edward W. The Complete Customer Service Letter Book. New York: McGraw-Hill, 1993.

Dyfyniad MLA

Werz, Edward W. The Complete Customer Service Letter Book. McGraw-Hill, 1993.

Rhybudd: Mae'n bosib nad yw'r dyfyniadau hyn bob amser yn 100% cywir.