SHAPIRO, B. Root Asymptotics for the Eigenfunctions of Univariate Differential Operators. Acta Polytechnica, [S. l.], v. 50, n. 5, 2010. DOI: 10.14311/1275. Disponível em: https://ojst.is.cvut.cz/ojs/index.php/ap/article/view/1275.. Acesso em: 13 may. 2025.