@book{51349,
	author = {Martin, William Ted. and Reissner, Eric.},
	title = {Elementary differential equations /},
	publisher = {Addision-Wesley publishing co.,},
	year = {c1956 [printing 1958].},
	series = {Addision-wesley mathematics series.},
	address = {Massachusetts :},
	note = {Includes index.}
}