HUANG, Sen-Zhong; RENDER, Hermann; WOLFF, Manfred P. H. On the convergence of sequences of operators and the convergence of the sequence of their spectra. Mathematica Scandinavica, Berkeley, CA, United States, v. 85, n. 1, p. 71–78, 1999. DOI: 10.7146/math.scand.a-13885. Disponível em: https://journals.msp.org/mscand/article/view/943. Acesso em: 24 jul. 2026.