Albert Krohn Michael Beigl Mike Hazas Hans-Werner Gellersen Using Fine-Grained Infrared Positioning to Support the Surface-Based Activities of Mobile Users. 463-468 2005 conf/icdcsw/2005 ICDCS Workshops http://doi.ieeecomputersociety.org/10.1109/ICDCSW.2005.139 db/conf/icdcsw/icdcsw2005.html#KrohnBHG05