RABANOVYCH, V. I. On Decompositions of a Scalar Operator into a Sum of Self-Adjoint Operators with Finite Spectrum. Ukrains’kyi Matematychnyi Zhurnal, [S. l.], v. 67, n. 5, p. 701–716, 2015. Disponível em: https://umj.imath.kiev.ua/index.php/umj/article/view/2016. Acesso em: 5 dec. 2025.