1. Basic Ideas and Concepts of Differential Geometry;Alexseevsky,1991
2. Geometrical Methods in the Theory of Ordinary Differential Equations;Arnold,1988
3. Symmetry and Perturbation Theory in Nonlinear Dynamics;Cicogna,1999
4. Symmetries and Conservation Laws for Differential Equations of Mathematical Physics;Krasil’schik,1999
5. Application of Lie Groups to Differential Equations;Olver,1986