TEPOYAN, L. P.; KALVAND, Daryoush. NEUMANN PROBLEM FOR FOURTH ORDER DEGENERATE ORDINARY DIFFERENTIAL EQUATIONS. Proceedings of the YSU A: Physical and Mathematical Sciences, Yerevan, Armenia, v. 44, n. 1 (221), p. 22–26, 2010. DOI: 10.46991/PYSU:A/2010.44.1.022. Disponível em: https://journals.ysu.am/index.php/proceedings-phys-math/article/view/vol44_no1_2010_pp022-026. Acesso em: 22 jul. 2024.