Cowan, D. S. (1968). Advertising in the 21st century: A model of advertising agency development during the next fifty years. London: Hutchinson.
Παραπομπή Chicago StyleCowan, D. S. Advertising in the 21st Century: A Model of Advertising Agency Development During the Next Fifty Years. London: Hutchinson, 1968.
Παραπομπή MLACowan, D. S. Advertising in the 21st Century: A Model of Advertising Agency Development During the Next Fifty Years. London: Hutchinson, 1968.
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