KazankoО. and PenkinaО. (2023) “Analysis and methodology of determining the norm of eigenfunctions as a limit transition in the scalar product in the spectral Stourm-Louvile problem for a photonic one-dimensional crystal”, Visnyk of V.N. Karazin Kharkiv National University, series “Radio Physics and Electronics”, (39), pp. 18-26. doi: 10.26565/2311-0872-2023-39-02.