@book{12609,
	author = {Colberg, Marshall R., and Alt, Richard M.},
	title = {Business economics;},
	publisher = {Irwin,},
	year = {1970.},
	address = {Homewood, Ill.,},
	edition = {4th ed.},
	note = {1951 ed. by R. M. Alt and W. C. Bradford.}
}