Y.K. Khudayberganov1, and J.I. Sharipov. “ILL-POSED INITIAL–BOUNDARY VALUE PROBLEM FOR A SYSTEM OF MIXED-TYPE EQUATIONS WITH TWO DEGENERATE PLANES”. IMRAS, vol. 9, no. 5, Aug. 2026, pp. 137-52, https://journal.imras.org/index.php/sps/article/view/2971.