ČIEGIS, R.; ŠTIKONAS, A.; ŠTIKONIENE, O.; SUBOČ, O. Stationary problems with nonlocal boundary conditions. Mathematical Modelling and Analysis, [S. l.], v. 6, n. 2, p. 178–191, 2001. DOI: 10.3846/13926292.2001.9637157. Disponível em: https://journals.vilniustech.lt/index.php/MMA/article/view/9897. Acesso em: 17 may. 2025.