1. Symmetry and Integration Methods for Differential Equations;Bluman,2002
2. Symmetries and Differential Equations;Bluman,1989
3. Symmetry Analysis and Exact Solutions of Equations of Nonlinear Mathematical Physics;Fushchych,1993
4. Applications of Lie Groups to Differential Equations;Olver,1993
5. The Group Analysis of Differential Equations;Ovsiannikov,1982