DJORDJEVIĆ, S. V. The Proper Elements and Simple Invariant Subspaces. Communications in Mathematics and Applications, [S. l.], v. 3, n. 1, p. 17–23, 2012. DOI: 10.26713/cma.v3i1.141. Disponível em: https://www.rgnpublications.com/journals/index.php/cma/article/view/141. Acesso em: 4 may. 2024.