@inproceedings{LiebchenSwarat2008, author = {Liebchen, Christian and Swarat, Elmar}, title = {The Second Chvatal Closure Can Yield Better Railway Timetables}, series = {ATMOS 2008 - 8th Workshop on Algorithmic Approaches for Transportation Modeling, Optimization, and Systems}, booktitle = {ATMOS 2008 - 8th Workshop on Algorithmic Approaches for Transportation Modeling, Optimization, and Systems}, editor = {Fischetti, Matteo and Widmayer, Peter}, publisher = {Schloss Dagstuhl - Leibniz-Zentrum fuer Informatik, Germany}, address = {Dagstuhl, Germany}, doi = {10.4230/OASIcs.ATMOS.2008.1580}, url = {http://nbn-resolving.de/urn:nbn:de:0030-drops-15802}, year = {2008}, language = {en} } @inproceedings{BorndoerferLiebchen2008, author = {Bornd{\"o}rfer, Ralf and Liebchen, Christian}, title = {When Periodic Timetables are Suboptimal}, series = {Operations Research Proceedings 2007}, booktitle = {Operations Research Proceedings 2007}, editor = {Kalcsics, J{\"o}rg and Nickel, Stefan}, publisher = {SPRINGER}, pages = {449 -- 454}, year = {2008}, language = {en} }