Popova, N.D. and Strilets, O.V. 2021. Criteria for the existence of systems of subspaces related to a certain class of unicyclic graphs. Ukrains’kyi Matematychnyi Zhurnal. 73, 4 (Apr. 2021), 556 - 565. DOI:https://doi.org/10.37863/umzh.v73i4.6354.