@book{644,
	author = {MCCNNELL, C.R. and STANLEY,L.BRUE & SEAN, M. FLYNN.},
	title = {Macroeconomics:  Principles, Problems, and Policies.},
	publisher = {McGraw-Hill,},
	year = {2012.},
	address = {New York,},
	edition = {19th Ed.}
}