GANIEVICH, R. D. ON CALCULATION OF MULTIPLE EIGENVALUES OF THE LINEAR OPERATOR-FUNCTION BY REDUCTION PSEUDO-PERTURBATION METHODS. IIUM Engineering Journal, [S. l.], v. 14, n. 2, 2013. DOI: 10.31436/iiumej.v14i2.438. Disponível em: https://journals.iium.edu.my/ejournal/index.php/iiumej/article/view/438. Acesso em: 4 feb. 2023.