@book{556,
	author = {Walker, Gordon,},
	title = {Modern competitive strategy /},
	publisher = {McGraw-Hill/Irwin,},
	year = {c2004.},
	address = {Boston :},
	note = {Includes index.},
	url = {http://www.loc.gov/catdir/description/mh031/2003048743.html}
}