Books and Lecture Notes

2. " Diskrete Mathematik und Logik für Informatiker" (2001, in German)
1. "Tools and Techniques in Modal Logic", Studies in Logic and the Foundations of Mathematics No. 142, Elsevier, Amsterdam, 1999.

Articles

23. "Elementary Models for Modal Predicate Logics, Part 2: Modal Individuals Revisited", in Reinhard Kahle (ed.): "Intensionality", 2005, 60 - 96. (with Oliver Kutz).
22. Notes On Substitution in First-Order Logic", in: Vincent Hendricks, Fabian Neuhaus, Stig-Andur Pedersen, Uwe Scheffler, Heinrich Wansing (eds.): First-Order Logic Revisited, Logos Verlag, Berlin, 2004, 155 - 172.
21. " Notes on the Space Requirements for Checking Satisfiability in Modal Logics", IN: Philippe Balbiani, Nobo-Yuki Suzuki, Frank Wolter and Michael Zakaryaschev (eds.): Advances in Modal Logic 4, King's College Publications, 2003, 243 - 264.
20. "Invariant Logics", Mathematical Logic Quarterly 48(2002), 29 - 50.
19. "Atomic Incompleteness of how to kill one bird with two stones", Bulletin of Section Logic 30/2(2001), 71 - 78.
18. "Elementary Models for Modal Predicate Logic. Part I: Completeness", in: F. Wolter, M. de Rijke, H. Wansing, and M. Zakharyaschev (eds.): Proceedings of AiML 2000 (with Oliver Kutz).
17. "V. V. Rybakov: Admissibility of Inference Rules." (Review), Notre Dame Journal of Formal Logic 40(1999), 578 - 587.
16. "Modal Logics that Need Very Large Frames", Notre Dame Journal of Formal Logic 40(1999), 141 - 173.
15. "Lattices of Modal Logics and Their Groups of Automorphisms", Annals of Pure and Applied Logic 100(1999), 99 - 139.
14. "Normal monomodal logics can simulate all others", Journal of Symbol Logic 64(1999), 99 - 138 (with Frank Wolter).
13. "On Extensions of Intermediate Logics by Strong Negation", Journal of Philosophical Logic 27(1998), 49 - 73.
12. "Simulation and Transfer Results in Modal Logic -- A Survey", Studia Logica 59(1997), 149 - 177 (with Frank Wolter).
11. "Power and Weakness of the Modal Display Calculus", in: Heinrich Wansing (ed.): "Proof Theory of Modal Logic", Studies in Applied Logic Vol. 2, Kluwer, Dordrecht, 1996, 95 - 122.
10. "Gumm's Theorem and the Structure of Minimal Algebras", Algebra Universalis 33(1995), 142 - 146.
9. "Highway to the Danger Zone", Journal of Logic and Computation 5(1995), 93 - 109.
8. "Prefinitely axiomatizable modal and intermediate logics", Mathematical Logic Quarterly 39(1993), 301 - 322.
7. "How Completeness and Correspondence Theory Got Married", in: Maarten de Rijke (ed.): "Diamonds and Defaults", Synthese Library vol. 229, Kluwer Academic Publishers, 1993, 175 - 214.
6. "Splittings and the finite model property", Journal of Symbolic Logic 58(1993), 139 - 157.
5. "Even more about the lattice of tense logics", Archive of Mathematical Logic 31(1992), 243 - 257.
4. "Properties of Independently Axiomatizable Bimodal Logics", Journal of Symbolic Logic 56(1991), 1469 - 1485 (with Frank Wolter).
3. "A Solution to a Problem of Urquhart", Journal of Philosophical Logic 20(1991), 285 -- 286.
2. "Internal Definability and Completeness in Modal Logic", PhD Thesis, Department of Mathematics, FU Berlin, 1991.
1. "An Almost General Splitting Theorem For Modal Logic, Studia Logica 49(1990), 455 -- 470.

In Preparation

5. "Sahlqvist Horn Logics Have Interpolation, Manuscript, UCLA, 2005.
4. "Logically Possible Worlds and Counterparts", to appear in Dale Jacquette (editor): Philosophy of Logic, Elsevier. (Together with Oliver Kutz.)
3. "The Global Decidability of K x K.♦ □ p → ▪ ◊ p and related logics", Manuscript (to appear in a paper together with Philippe Balbiani, Jen Davoren and Raj Goré) (if the title is garbled it is because your browser like mine refuses to support the whole SGML fontset!)
2. "Semisimple Varieties of Modal Algebras", to appear in Studia Logica. (Together with Tomasz Kowalski.)
1. "Modal Consequence Relations", to appear in: Johan van Benthem, Yde Venema and Frank Wolter: Handbook of Modal Logic, Elsevier.