@book{28557,
	author = {Derrick, William R. and Grossman, Stanley I.},
	title = {Elementary differential equations with applications},
	publisher = {Addison-Wesley Pub. Co.},
	year = {c1976.},
	series = {Addison-Wesley series in mathematics},
	address = {Reading, Mass.},
	note = {Includes index.}
}