Рыскан A., and T. Ergashev. “CONSTRUCTION OF A SOLUTION TO A BOUNDARY VALUE PROBLEM WITH N-D CONDITIONS FOR THE FOUR-DIMENSIONAL GELLERSTEDT EQUATION”. Bulletin of the Abai KazNPU, the series of "Physical and Mathematical Sciences" 83, no. 3 (September 27, 2023): 16–24. Accessed July 3, 2024. https://bulletin-phmath.kaznpu.kz/index.php/ped/article/view/1732.