BASKAKOV, A.; KRISHTAL, I.; USKOVA, N. B. On the Spectral Analysis of a Differential Operator with an Involution and General Boundary Conditions. Eurasian Mathematical Journal, [S. l.], v. 11, n. 2, p. 30–39, 2020. DOI: 10.32523/2077-9879-2020-11-2-30-39. Disponível em: https://emj.enu.kz/index.php/main/article/view/176. Acesso em: 30 sep. 2026.