@incollection {kofod-petersen11:_model_with_probl_frames,
  author =	 {Anders Kofod-Petersen and J\"{o}rg Cassens},
  title =	 {Modelling with Problem Frames: Explanations and
                  Context in Ambient Intelligent Systems},
  booktitle =	 {Modeling and Using Context},
  series =	 {Lecture Notes in Computer Science},
  editor =	 {Michael Beigl and Henning Christiansen and Thomas
                  Roth-Berghofer and Anders Kofod-Petersen and Kenny
                  Coventry and Hedda Schmidtke},
  publisher =	 {Springer Berlin / Heidelberg},
  pages =	 {145-158},
  volume =	 6967,
  year =	 2011
}