Teplins’kyiO. Y. (1998) “Asymptotic solution of one-dimensional spectral boundary-value problems with rapidly varying coefficients: The case of multiple spectra”, Ukrains’kyi Matematychnyi Zhurnal, 50(10), pp. 1399–1408. Available at: https://umj.imath.kiev.ua/index.php/umj/article/view/4825 (Accessed: 28November2024).