BOKHONOV , Yu. E. Commutating self-conjugate expansion of the system of Hermitian operators. Ukrains’kyi Matematychnyi Zhurnal, [S. l.], v. 40, n. 2, p. 149–153, 1988. Disponível em: https://umj.imath.kiev.ua/index.php/umj/article/view/9110. Acesso em: 7 dec. 2025.