@book{39504,
	author = {Engel, James F. and Warshaw, Martin R.,},
	title = {Promotional strategy},
	publisher = {Irwin},
	year = {1987.},
	series = {The Irwin series in marketing},
	address = {Homewood, Ill.},
	edition = {6th ed.},
	note = {920316}
}