HARISH, V. K.; BALASUBRAMANI, M. S. A new metric in the study of shift invariant subspaces of $L^2(\mathbb{R}^n)$. Methods of Functional Analysis and Topology, [S. l.], v. 18, n. 3, p. 214–219, 2012. Disponível em: https://zen.imath.kiev.ua/index.php/mfat/article/view/517. Acesso em: 16 dec. 2025.