Kaplan, Wilfred, 1915- Elements of differential equations / by Wilfred Kaplan - Reading, Mass. ; London : Addison-Wesley Pub. Co, 1964 - xi, 270 p. 23cm - Addision-wesley series in mathematics. . - Addision-wesley series in mathematics. . Subjects--Topical Terms: Differential equations Dewey Class. No.: 515.35 / KAE 1964