@book{324,
	author = {Lipsey, Richard G., and Chrystal, K. Alec.},
	title = {Principles of economics /},
	publisher = {Oxford University Press,},
	year = {1999.},
	address = {Oxford ;},
	edition = {9th ed.},
	note = {Rev. ed. of: An introduction to positive economics. 8th ed. 1995.}
}