Boyko, O.P., Martynyuk, O.M. and Pivovarchik, V.N. (2021) “On the second largest multiplicity of eigenvalues for the Stieltjes string spectral problem on trees”, Methods of Functional Analysis and Topology, 27(3), pp. 217–226. doi:https://doi.org/10.31392/MFAT-npu26_3.2021.03.