LANKE, J. On the Asymptotic Distribution of Eigenvalues of Certain One-Dimensional Sturm-Liouville Operators. MATHEMATICA SCANDINAVICA, [S. l.], v. 9, p. 69–79, 1961. DOI: 10.7146/math.scand.a-10623. Disponível em: https://www.mscand.dk/article/view/10623. Acesso em: 29 apr. 2024.