@INPROCEEDINGS{Kessler-ECMR-2011,
  author = {Kessler, Jens and Scheidig, Andrea and Gross, Horst-Michael},
  title = {Approaching a Person in a Socially Acceptable Manner Using Expanding
    Random Trees},
  booktitle = {Europ. Conf. on Mobile Robots (ECMR)},
  year = {2011},
  pages = {95--100}
}