Roman Kontchakov Ian Pratt-Hartmann Frank Wolter Michael Zakharyaschev Topology, connectedness, and modal logic. 151-176 2008 Advances in Modal Logic http://www.aiml.net/volumes/volume7/Kontchakov-PrattHartmann-Wolter-Zakharyaschev.pdf conf/aiml/2008 db/conf/aiml/aiml2008.html#KontchakovPWZ08