V. Lakeyev, A., V. A. Rusanov, A. V. Banshchikov, and R. A. Daneev. 2024. “ON FINITE CHARACTER GEOMETRICAL PROPERTY OF THE DIFFERENTIAL REALIZATION OF NONSTATIONARY HYPERBOLIC SYSTEMS”. Advances in Differential Equations and Control Processes 31 (2). https://ojs.acad-pub.com/index.php/ADECP/article/view/2433.