Boyce, William E. Elementary differential equations and boundary value problems/ William E. Boyce and Richard C. Di Prima. - 2d ed. - New York: Wiley, [1969]. - xiv, 533, A-43, I-8 p.: illus., 24 cm. Bibliography: p. 533. ISBN: 0471093319 LCCN: 69016043 //r88 Nat. Bib. No.: GB69-17472 Subjects--Topical Terms: Differential equations.Boundary value problems. Dewey Class. No.: 515.35 / B789e