GORBACHUK, M. L.; YAKYMIV, R. Ya. Estimate of error of an approximated solution by the method of moments of an operator equation. Ukrains’kyi Matematychnyi Zhurnal, [S. l.], v. 48, n. 11, p. 1477–1483, 1996. Disponível em: https://umj.imath.kiev.ua/index.php/umj/article/view/5201. Acesso em: 5 dec. 2025.