1. New similarity solutions of the Boussinesq equation;Clarkson;J. Math. Phys.,1989
2. Similarity methods for differential equations;Bluman;Appl. Math. Sci.,1974
3. Symmetries and differential equations;Bluman;Appl. Math. Sci.,1989
4. Differential Equations and Group Methods for Scientists and Engineers;Hill,1992
5. Applications of Lie groups to differential equations;Olver,1986