PROBLEMS WITH INTEGRAL AND BITSADZE-SAMARSKY CONDITION FOR A SECOND-ORDER PARABOLIC-HYPERBOLIC EQUATION WITH A SINGULAR COEFFICIENT . SJFSU [Internet]. 2023 Jul. 11 [cited 2025 Dec. 25];28(2):43. Available from: https://journal.fdu.uz/index.php/sjfsu/article/view/1940