KazankoО., and PenkinaО. “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”, no. 39, Dec. 2023, pp. 18-26, doi:10.26565/2311-0872-2023-39-02.