BEKKER, M. B.; CIMA, J. A. An Operator Approach to Extremal Problems on Hardy and Bergman Spaces. Methods of Functional Analysis and Topology, [S. l.], v. 27, n. 2, p. 142–150, 2021. DOI: https://doi.org/10.31392/MFAT-npu26_2.2021.02. Disponível em: https://zen.imath.kiev.ua/index.php/mfat/article/view/790. Acesso em: 15 dec. 2025.