SHEHDA, L. M. DEGENERATE BOUNDARY-VALUE PROBLEMS WITH A PERTURBING MATRIX FOR A DERIVATIVE: Array. PRECARPATHIAN BULLETIN OF THE SHEVCHENKO SCIENTIFIC SOCIETY. Number, [S. l.], n. 1(59), p. 29–37, 2021. DOI: 10.31471/2304-7399-2020-1(59)-29-37. Disponível em: https://pvntsh.nung.edu.ua/index.php/number/article/view/1598. Acesso em: 29 mar. 2024.