Stein, Benno, Oliver Niggemann, and Theodor Lettmann. “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, 273--278, 2006.
LibreCat: /record/3327

Kleine Büning, Hans, and Theodor Lettmann. “Resolution Remains Hard under Equivalence.”https://doi.org/10.1016/s0166-218x(99)00055-4__Discrete Applied Mathematics, 1999, 139–48.https://doi.org/10.1016/s0166-218x(99)00055-4 .
LibreCat: /record/19815
DOI: 10.1016/s0166-218x(99)00055-4

Lettmann, Theodor, and Hans Kleine Büning. Propositional Logicf: Deduction and Algorithms. Cambridge Tracts in Theoretical Computer Science. Cambridge Univ. Press, 1999.
LibreCat: /record/3339

Kleine Büning, Hans, and Theodor Lettmann. “Learning a Representation for Optimizable Formulas.”https://doi.org/10.1007/3-540-61863-5_33__In Lecture Notes in Computer Science. Berlin, Heidelberg, 1996.https://doi.org/10.1007/3-540-61863-5_33 .
LibreCat: /record/19816
DOI: 10.1007/3-540-61863-5_33

Kleine Büning, Hans, and Theodor Lettmann. Aussagenlogik - Deduktion und Algorithmen. Leitfäden und Monographien der Informatik. Teubner, 1994.https://doi.org/10.1007/978-3-322-84809-3 .
LibreCat: /record/3333
DOI: 10.1007/978-3-322-84809-3

Flögel, A., H. Kleine Büning, and Theodor Lettmann. “On the Restricted Equivalence for Subclasses of Propositional Logic.”https://doi.org/10.1051/ita/1993270403271__RAIRO - Theoretical Informatics and Applications, 1993, 327–40.https://doi.org/10.1051/ita/1993270403271 .
LibreCat: /record/19814
DOI: 10.1051/ita/1993270403271

Dahn, Bernd I., Theodor Lettmann, and Wolfgang Schönfeld. ILFA Interface Concept. Vol. 193. IWBS Report. ´Heidelberg: Wissenschaftliche Zentrum der IBM Deutschland , 1991.
LibreCat: /record/19822

Kleine Büning, Hans, Theodor Lettmann, and Ernst W. Mayr. “Projections of Vector Addition System Reachability Sets Are Semilinear.”https://doi.org/10.1016/0304-3975(89)90055-8__Theoretical Computer Science, 1989, 343–50.https://doi.org/10.1016/0304-3975(89)90055-8 .
LibreCat: /record/19818
DOI: 10.1016/0304-3975(89)90055-8

Kleine Büning, Hans, and Theodor Lettmann. “Perspektiven Für Die Logikprogrammierung.” In Workshop Wissensrepräsentation in Expertensystemen, edited by G. Rahmstorf, 56–78. Berlin, Heidelberg, 1988.
LibreCat: /record/19820

Büning, Hans Kleine, and Theodor Lettmann. “Representation Independent Query and Update Operations on Propositional Definite Horn Formulas.”https://doi.org/10.1007/3-540-18170-9_167__In Computation Theory and Logic, edited by Egon Börger, 208–23. Berlin, Heidelberg, 1987.https://doi.org/10.1007/3-540-18170-9_167 .
LibreCat: /record/19821
DOI: 10.1007/3-540-18170-9_167

Kleine Büning, H., and Theodor Lettmann. “Classes of First Order Formulas under Various Satisfiability Definitions.”https://doi.org/10.1007/3-540-16780-3_119__In 8th International Conference on Automated Deduction. Berlin, Heidelberg, 1986.https://doi.org/10.1007/3-540-16780-3_119 .
LibreCat: /record/19819
DOI: 10.1007/3-540-16780-3_119