@InProceedings{guinard2007permid,
  author = {D. Guinard, S. Streng, H. Gellersen},
  title  = "{A User Interface for Spontaneous Interaction with Pervasive Services}",
  booktitle = {Mobile Spatial Interaction Workshop in conjunction with Conference on Human Factors in Computing Systems 2007 (CHI 2007), San Jose, CA, USA, April 2007},
  month = april,
  year =   {2007}
  }