STRAUSS, V. A. On models of function type for a special class of normal operators in Krein spaces and their polar representation. Methods of Functional Analysis and Topology, [S. l.], v. 13, n. 1, p. 67–82, 2007. Disponível em: https://zen.imath.kiev.ua/index.php/mfat/article/view/338. Acesso em: 16 dec. 2025.