@book{70170,
	author = {Colberg, Marshall Rudolph, and Alt, Richard M.},
	title = {Business economics :},
	publisher = {Irwin,},
	year = {1986.},
	address = {Homewood :},
	edition = {7th ed.},
	note = {1951 ed. by R. M. Alt and W. C. Bradford.}
}