[1] R. L. Anderson N. H. Ibragimov:
Lie-Bäcklund Transformations in Applications. SIAM Philadelphia 1979.
MR 0520395
[2] M. J. Ablowitz M. Segur:
Solitons and the Inverse Scattering Transform. SIAM Philadelphia 1981 (Russian transl. Moskva 1987).
MR 0642018
[3] J. Chrastina:
On formal theory of differential equations. Časopis pro pěst. matem. Praha; Part I, vol. 111 (1986), 353-383; Part II, vol. 114 (1989), 60-105; Part III (to appear).
Zbl 0638.35008
[4] J. Chrastina:
Formal Calculus of Variations on Fibered Manifolds. Folia UJEP Brno 1989, Mathematica 2.
MR 1036730 |
Zbl 0696.49075
[5] N. H. Ibragimov:
Transformation Groups in Mathematical Physics. (Russian), Moskva, Nauka 1983.
MR 0734307 |
Zbl 0529.53014
[6] Ju. I. Manin:
Algebraic aspects of nonlinear differential equations. (Russian), Itogi Nauki i Techniki VINITI Ser. Sovrem. Problemy matematiki 11 (1978), 5-152.
MR 0501136
[7] P. J. Olver:
Applications of Groups to Differential Equations. Springer-Verlag 1986.
MR 0836734
[8] V. V. Sokolov:
On the symmetries of evolutional equations. (Russian), Uspěchi matem. nauk 43, vyp. 5 (263) 1988, 133-163.
MR 0971467