@InProceedings{triebel06:multi,
  author = 	 {Rudolph Triebel and Patrick Pfaff and Wolfram Burgard},
  title = 	 {Multi-Level Surface Maps for Outdoor Terrain Mapping and Loop Closing},
  booktitle = 	 {"Proc.~of the International Conference on Intelligent Robots and Systems (IROS)"},
  year =	 2006
}