FRASEN ROBINSON JOHN. (1989). SECRETS OF EFFECTIVE DIRECT MAIL. MCGRAW-HILL.
Dyfyniad Arddull ChicagoFRASEN ROBINSON JOHN. SECRETS OF EFFECTIVE DIRECT MAIL. LONDON: MCGRAW-HILL, 1989.
Dyfyniad MLAFRASEN ROBINSON JOHN. SECRETS OF EFFECTIVE DIRECT MAIL. MCGRAW-HILL, 1989.
Rhybudd: Mae'n bosib nad yw'r dyfyniadau hyn bob amser yn 100% cywir.