SANATI, R. G.; ANSARI-PIRI, E.; KARDEL, M. Operators preserving orthogonality on Hilbert $\it{K}(H)$-modules. Methods of Functional Analysis and Topology, [S. l.], v. 25, n. 2, p. 189–194, 2019. Disponível em: https://zen.imath.kiev.ua/index.php/mfat/article/view/722. Acesso em: 16 dec. 2025.