TEPLINS’KYI, O. Yu. Asymptotic solution of one-dimensional spectral boundary-value problems with rapidly varying coefficients: The case of multiple spectra. Ukrains’kyi Matematychnyi Zhurnal, [S. l.], v. 50, n. 10, p. 1399–1408, 1998. Disponível em: https://umj.imath.kiev.ua/index.php/umj/article/view/4825. Acesso em: 5 dec. 2025.