Dyfyniad APA

Geffner, A. B. (1991). Business letters the easy way. New York: Barron’s.

Dyfyniad Arddull Chicago

Geffner, Andrea B. Business Letters the Easy Way. New York: Barron’s, 1991.

Dyfyniad MLA

Geffner, Andrea B. Business Letters the Easy Way. New York: Barron’s, 1991.

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