Ince E.L. Ordinary Differential Equations

Dover Publications, 1956. — 558 pages.Among the topics covered in this classic treatment are linear differential equations; solution in an infinite form; solution by definite integrals; algebraic theory; Sturmian theory and its later developments; further developments in the theory of boundary problems; existence theorems, equations of first order; nonlinear equations of higher order; linear equations in complex domain; and oscillation theorems in the complex domain.