Boyce, William E. Elementary differential equations and boundary value problems / William E. Boyce, Richard C. DiPrima - 7th ed. - New York: Wiley, c2001 - xvi, 745 p. : col. ill. ; 26 cm. Includes bibliographical references and index ISBN: 0471319996 Subjects--Topical Terms: Differential equationsBoundary value problems