S. Kikot, I. Shapirovsky, and E. Zolin. Modal logics with transitive closure: completeness, decidability, filtration. In Advances in Modal Logic, volume 13, pages 369–388, 2020. ISBN 978-1-84890-341-8. https://arxiv.org/pdf/2011.02205.pdf

Filtration safe operations on frames. In Advances in Modal Logic 10, invited and contributed papers from the tenth conference on "Advances in Modal Logic," held in Groningen, The Netherlands, August 5-8, 2014, pages 333-352, 2014.
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