USTILKO, Ekaterina V.; LOMOVTSEV, Fiodar E. Matching conditions for values of characteristic oblique derivative at the end of a string, initial data and right-hand side of the wave equation. Journal of the Belarusian State University. Mathematics and Informatics, [S. l.], n. 1, p. 30–37, 2020. DOI: 10.33581/2520-6508-2020-1-30-37. Disponível em: https://journals.bsu.by/index.php/mathematics/article/view/1098. Acesso em: 17 jul. 2026.