HUANG, S.-Z.; RENDER, H.; WOLFF, M. P. H. On the convergence of sequences of operators and the convergence of the sequence of their spectra. MATHEMATICA SCANDINAVICA, [S. l.], v. 85, n. 1, p. 71–78, 1999. DOI: 10.7146/math.scand.a-13885. Disponível em: https://www.mscand.dk/article/view/13885. Acesso em: 6 may. 2024.