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Dyfyniad Arddull ChicagoRIES AL. BOTTOM-UP MARKETING. NEW YORK: MCGRAW-HILL, 1989.
Dyfyniad MLARIES AL. BOTTOM-UP MARKETING. MCGRAW-HILL, 1989.
Rhybudd: Mae'n bosib nad yw'r dyfyniadau hyn bob amser yn 100% cywir.