1. Noether, E.,Nachr. Kgl. Ges. Wiss. Göttingen, Math.-Phys. Kl., 235–257 (1918).
2. Ibragimov, N.H.,Theor. Mat. Phys. 1, No. 3, 350–359.
3. Ibragimvo, N.H.,Proc. of Symposium: Symmetry, Similarity and Group Theoretic Methods in Mechanics, University of Calgary, Aug. 19–21 (1974), pp. 63–82.
4. Ibragimov, N.H. and Anderson, R.L.,Dokl. Akad. Nauk S.S.S.R. 227, No. 3 (1970).
5. Ibragimov, N.H.,Dokl. Akad. Nauk S.S.S.R. 230, No. 1 (1976).