1. [1] Shilov G.E. On conditions of correctness of Cauchy’s problem for systems of partial differential equations with constant coefficients Uspekhi Mat. Nauk. 1955, 10 (4), 89–100. (in Russian)
2. [2] I. Gel’fand and G. Shilov Generalized Functions. Vol. 3. Theory of Differential Equations. Boston, MA: Academic Press, 1967.
3. [3] Zhitomirskii Ya.I. Cauchy problem for some types of systems of linear equations, which are parabolic by G.E. Shilov, with partial derivatives with continuous coefficients Izv. AN SSSR. Ser. Mat. 1959, 23, 925–932. (in Russian)
4. [4] U. Hou-Sin On the definition of parabolicity of systems of equations with partial derivatives Uspekhi Mat. Nauk. 1960, 15 (6), 157–161. (in Russian)
5. [5] S.D. Eidelman, S.D. Ivasishen, and F.O. Porper The Liouville theorems for systems parabolic by Shilov Izv. Vyzov. Mat. 1961, (6), 169–179. (in Russian)