2 citations to https://www.mathnet.ru/rus/rm9442

1. A. V. Kudinov, “Topological Product of Modal Logics with the McKinsey Axiom”, Dokl. Math., 2024  
2. Shehtman V., “Segerberg Squares of Modal Logics and Theories of Relation Algebras”, Larisa Maksimova on Implication, Interpolation, and Definability, Outstanding Contributions to Logic, 15, ed. Odintsov S., Springer, 2018, 245–296