@article{FerreinSchifferLakemeyer2011,
  author    = {Alexander Ferrein and Stefan Schiffer and Gerhard Lakemeyer},
  title     = {Qualitative World Models for Soccer Robots / Schiffer, Stefan ; Ferrein, Alexander ; Lakemeyer, Gerhard},
  journal   = {Qualitative constraint calculi : application and integration ; KI 2006, 14 - 19 June 2006, Bremen, Germany ; 29th Annual German Conference on Artificial Intelligence ; workshop / Stefan W{\"o}lfl ... (eds.)},
  pages     = {3 -- 14},
  year      = {2011},
}