ZOLOTAREV, V. A.; LEVCHUK, V. N. On a function system making a basis in a weight space. Methods of Functional Analysis and Topology, [S. l.], v. 23, n. 3, p. 261–269, 2017. Disponível em: https://zen.imath.kiev.ua/index.php/mfat/article/view/669. Acesso em: 15 dec. 2025.