APA সাইটেশন

Cowan, D. S. (1968). Advertising in the 21st century: A model of advertising agency development during the next fifty years. London: Hutchinson.

শিকাগো স্টাইলে সাইটেশন

Cowan, D. S. Advertising in the 21st Century: A Model of Advertising Agency Development During the Next Fifty Years. London: Hutchinson, 1968.

এমএলএ সাইটেশন

Cowan, D. S. Advertising in the 21st Century: A Model of Advertising Agency Development During the Next Fifty Years. London: Hutchinson, 1968.