Programmatic Task Network Planning
F. Mohr, T. Lettmann, E. Hüllermeier, M.D. Wever, in: Proceedings of the 1st ICAPS Workshop on Hierarchical Planning, AAAI, 2018, pp. 31–39.

Certiû01cation Matters for Service Markets
M.-C. Jakobs, J. Krämer, D. van Straaten, T. Lettmann, in: T.P. Marcelo De Barros, Janusz Klink,Tadeus Uhl (Ed.), The Ninth International Conferences on Advanced Service Computing (SERVICE COMPUTATION), 2017, pp. 7–12.

Planning with Independent Task Networks
F. Mohr, T. Lettmann, E. Hüllermeier, in: Proc. 40th Annual German Conference on Advances in Artificial Intelligence (KI 2017), 2017, pp. 193–206.

Reducing Nondeterminism in Automated Service Composition
F. Mohr, T. Lettmann, H. Kleine Büning, in: Proceedings of the 6th International Conference on Service Oriented Computing and Applications (SOCA), 2013, pp. 154–161.

Modeling Agents and Agent Systems
T. Lettmann, M. Baumann, M. Eberling, T. Kemmerich, Transactions on Computational Collective Intelligence V (2011) 157–181.

Speeding Up Model-based Diagnosis by a Heuristic Approach to Solving SAT
B. Stein, O. Niggemann, T. Lettmann, in: AIA ’06: Proceedings of the 24th IASTED International Conference on Artificial Intelligence and Applications, 2006, pp. 273--278.

Resolution remains hard under equivalence
H. Kleine Büning, T. Lettmann, Discrete Applied Mathematics (1999) 139–148.

Propositional Logic : Deduction and Algorithms
T. Lettmann, H. Kleine Büning, Propositional Logicf: Deduction and Algorithms, Cambridge Univ. Press, 1999.

Learning a representation for optimizable formulas
H. Kleine Büning, T. Lettmann, in: Lecture Notes in Computer Science, Berlin, Heidelberg, 1996.

Aussagenlogik - Deduktion und Algorithmen
H. Kleine Büning, T. Lettmann, Aussagenlogik - Deduktion und Algorithmen, Teubner, 1994.

On the restricted equivalence for subclasses of propositional logic
A. Flögel, H. Kleine Büning, T. Lettmann, RAIRO - Theoretical Informatics and Applications (1993) 327–340.

ILFA Interface Concept
B.I. Dahn, T. Lettmann, W. Schönfeld, ILFA Interface Concept, Wissenschaftliche Zentrum der IBM Deutschland , ´Heidelberg, 1991.

Projections of vector addition system reachability sets are semilinear
H. Kleine Büning, T. Lettmann, E.W. Mayr, Theoretical Computer Science (1989) 343–350.

Perspektiven für die Logikprogrammierung
H. Kleine Büning, T. Lettmann, in: G. Rahmstorf (Ed.), Workshop Wissensrepräsentation in Expertensystemen, Berlin, Heidelberg, 1988, pp. 56–78.

Representation independent query and update operations on propositional definite Horn formulas
H.K. Büning, T. Lettmann, in: E. Börger (Ed.), Computation Theory and Logic, Berlin, Heidelberg, 1987, pp. 208–223.

Classes of first order formulas under various satisfiability definitions
H. Kleine Büning, T. Lettmann, in: 8th International Conference on Automated Deduction, Berlin, Heidelberg, 1986.