YUDITSKII, Peter. Analytic perturbation preserves determinacy of infinite index. Mathematica Scandinavica, Berkeley, CA, United States, v. 86, n. 2, p. 288–292, 2000. DOI: 10.7146/math.scand.a-14294. Disponível em: https://journals.msp.org/mscand/article/view/911. Acesso em: 25 jul. 2026.