Mohr F, Lettmann T, Hüllermeier E, Wever MD. Programmatic Task Network Planning. In: Proceedings of the 1st ICAPS Workshop on Hierarchical Planning. AAAI; 2018:31-39.

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

Mohr F, Lettmann T, Hüllermeier E. Planning with Independent Task Networks. In: Proc. 40th Annual German Conference on Advances in Artificial Intelligence (KI 2017). ; 2017:193-206. doi:10.1007/978-3-319-67190-1_15

Mohr F, Lettmann T, Kleine Büning H. Reducing Nondeterminism in Automated Service Composition. In: Proceedings of the 6th International Conference on Service Oriented Computing and Applications (SOCA). ; 2013:154-161. doi:10.1109/SOCA.2013.25

Lettmann T, Baumann M, Eberling M, Kemmerich T. Modeling Agents and Agent Systems. Transactions on Computational Collective Intelligence V. 2011:157-181. doi:10.1007/978-3-642-24016-4_9

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

Kleine Büning H, Lettmann T. Resolution remains hard under equivalence. Discrete Applied Mathematics. 1999:139-148. doi:10.1016/s0166-218x(99)00055-4

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

Kleine Büning H, Lettmann T. Learning a representation for optimizable formulas. In: Lecture Notes in Computer Science. Berlin, Heidelberg; 1996. doi:10.1007/3-540-61863-5_33

Kleine Büning H, Lettmann T. Aussagenlogik - Deduktion und Algorithmen. Teubner; 1994. doi:10.1007/978-3-322-84809-3

Flögel A, Kleine Büning H, Lettmann T. On the restricted equivalence for subclasses of propositional logic. RAIRO - Theoretical Informatics and Applications. 1993:327-340. doi:10.1051/ita/1993270403271

Dahn BI, Lettmann T, Schönfeld W. ILFA Interface Concept. Vol 193. ´Heidelberg: Wissenschaftliche Zentrum der IBM Deutschland ; 1991.

Kleine Büning H, Lettmann T, Mayr EW. Projections of vector addition system reachability sets are semilinear. Theoretical Computer Science. 1989:343-350. doi:10.1016/0304-3975(89)90055-8

Kleine Büning H, Lettmann T. Perspektiven für die Logikprogrammierung. In: Rahmstorf G, ed. Workshop Wissensrepräsentation in Expertensystemen. Berlin, Heidelberg; 1988:56-78.

Büning HK, Lettmann T. Representation independent query and update operations on propositional definite Horn formulas. In: Börger E, ed. Computation Theory and Logic. Berlin, Heidelberg; 1987:208-223. doi:10.1007/3-540-18170-9_167

Kleine Büning H, Lettmann T. Classes of first order formulas under various satisfiability definitions. In: 8th International Conference on Automated Deduction. Berlin, Heidelberg; 1986. doi:10.1007/3-540-16780-3_119