Bell, M. L. (1979). Marketing, concepts and strategy (3d ed.). Houghton Mifflin.
Dyfyniad Arddull ChicagoBell, Martin L. Marketing, Concepts and Strategy. 3d ed. Boston: Houghton Mifflin, 1979.
Dyfyniad MLABell, Martin L. Marketing, Concepts and Strategy. 3d ed. Houghton Mifflin, 1979.
Rhybudd: Mae'n bosib nad yw'r dyfyniadau hyn bob amser yn 100% cywir.