V. I. Tsurkov U.S.S.R. Comput. Math. Math. Phys. , 8, No.4 , 01.1970 , p. 264-269, language: английский ISSN 0041-5553  Аннотация A priori estimates are obtained for variations of classical solutions to hyperbolic systems written in the form of Riemann invariants. They are bounded on non-eigen characteristics.  Ключевые слова variations of solutions, a priori estimates, weakly nonlinear hyperbolic systems