Dyfyniad APA

Guffey, M. E. (1999). Business English (6th ed.). Cincinnati, Ohio: South-Western College.

Dyfyniad Arddull Chicago

Guffey, Mary Ellen. Business English. 6th ed. Cincinnati, Ohio: South-Western College, 1999.

Dyfyniad MLA

Guffey, Mary Ellen. Business English. 6th ed. Cincinnati, Ohio: South-Western College, 1999.

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