Enrico Rukzio Gregor Broll Karin Leichtenstern Albrecht Schmidt Mobile Interaction with the Real World: An Evaluation and Comparison of Physical Mobile Interaction Techniques. 1-18 2007 conf/eusai/2007 AmI http://dx.doi.org/10.1007/978-3-540-76652-0_1 db/conf/eusai/ami2007.html#RukzioBLS07