BAYEV, A. The Lagrange principle and finite-dimensional approximations in the optimal inverse problem for linear operators. Numerical Methods and Programming (Vychislitel’nye Metody i Programmirovanie), [S. l.], v. 7, n. 10, p. 323–336, 2006. Disponível em: https://en.num-meth.ru/index.php/journal/article/view/224. Acesso em: 29 apr. 2024.