@book{13,
	author = {Stevenson, William J.},
	title = {Operations management /},
	publisher = {McMcGraw-Hill Irwin,},
	year = {c2009.},
	address = {Boston :},
	edition = {10th ed.},
	url = {http://www.loc.gov/catdir/toc/ecip0611/2006010876.html}
}