1. Invariante variations probleme, knigliche gesellschaft der wissenschaften zu gttingen;Noether;Nach Math Phys Klasse Heft,1918
2. Applications of Lie Groups To Differential Equations;Olver,1986
3. Local symmetries and conservation laws;Vinogradov;Acta Appl Math,1984
4. A new conservation theorem;Ibragimov;J Math Anal Appl,2007
5. Quasi self-adjoint differential equations;Ibragimov;Arch ALGA,2007