1. Lecture Notes in Computer Science;T. Bächler,2010
2. Graduate Texts in Mathematics;T. Becker,1993
3. Blinkov, Y.A., Cid, C.F., Gerdt, V.P., Plesken, W., Robertz, D.: The MAPLE Package Janet: II. Linear Partial Differential Equations. In: Ganzha, V.G., Mayr, E.W., Vorozhtsov, E.V. (eds.) Proceedings of the 6th International Workshop on Computer Algebra in Scientific Computing, pp. 41–54. Technische Universität München (2003),
http://wwwb.math.rwth-aachen.de/Janet
4. Cox, D., Little, J., O’Shie, D.: Ideals, Varieties and Algorithms: An Introduction to Computational Algebraic Geometry and Commutative Algebra, 3rd edn. Springer, New York (2007)
5. Dorodnitsyn, V.: The Group Properties of Difference Equations. Moscow, Fizmatlit (2001) (in Russian)