Rod McCall Ina Wagner Kari Kuutti Giulio Jacucci Wolfgang Broll Urban mixed realities: technologies, theories and frontiers. 3973-3976 2008 CHI Extended Abstracts http://doi.acm.org/10.1145/1358628.1358970 conf/chi/2008a db/conf/chi/chi2008a.html#McCallWKJB08