Underhill, P. (1999). Why we buy: The science of shopping. Simon & Schuster.
Dyfyniad Arddull ChicagoUnderhill, Paco. Why We Buy: The Science of Shopping. New York: Simon & Schuster, 1999.
Dyfyniad MLAUnderhill, Paco. Why We Buy: The Science of Shopping. Simon & Schuster, 1999.
Rhybudd: Mae'n bosib nad yw'r dyfyniadau hyn bob amser yn 100% cywir.