1. V.I. Arnold, Ordinary Differential Equations (MIT, Cambridge, 1978)
2. V.I. Arnold, Geometric Methods in the Theory of Differential Equations (Springer, New York, 1988)
3. I.N. Bronshtein, K.A. Semendayev, Handbook of Mathematics (Springer, Berlin, 2004)
4. C. Chicone, Ordinary Differential Equations with Applications (Springer, New York, 2006)
5. E.A. Coddington, N. Levinson, Theory of Ordinary Differential Equations (McGraw-Hill Book Co., New York, 1982)