THE ILL-POSEDNESS OF A MIXED PROBLEM IN A CYLINDRICAL DOMAIN FOR MULTIDIMENSIONAL HYPERBOLIC-ELLIPTIC EQUATIONS IN CANCER MODELING. Int. j. math. phys. [Internet]. 2026 Jun. 8 [cited 2026 Jul. 22];17(1):84-91. Available from: https://ijmph.kaznu.kz/index.php/kaznu/article/view/1246