Christian Decker Uwe Kubach Michael Beigl Revealing the Retail Black Box by Interaction Sensing. 328-333 2003 conf/icdcsw/2003 ICDCS Workshops http://csdl.computer.org/comp/proceedings/icdcsw/2003/1921/00/19210328abs.htm db/conf/icdcsw/icdcsw2003.html#DeckerKB03