@book{7889,
	author = {Spiegel, Murray R.},
	title = {Schaum's outline of theory and problems of calculus of finite differences and difference equations /},
	publisher = {McGraw-Hill,},
	year = {1971.},
	series = {Schaum's outline series},
	address = {New York :},
	note = {Cover title: Theory and problems of calculus of finite differences and difference equations.},
	url = {http://www.loc.gov/catdir/description/mh031/74151500.html}
}