@book{11737,
	author = {Richard G. Lipsey and Chrystal K. Alec },
	title = {An introduction to positive economics },
	publisher = {Oxford University Press, },
	year = {1995.},
	address = {Oxford :},
	edition = {7th ed.},
	note = {Spine title: Positive economics
7th ed originally published: London : Weidenfeld and Nicolson, 1989}
}