Claus M. Christensen Jesper Kjeldskov Klaus K. Rasmussen GeoHealth: a location-based service for nomadic home healthcare workers. 273-281 2007 OZCHI http://doi.acm.org/10.1145/1324892.1324951 conf/ozchi/2007 db/conf/ozchi/ozchi2007.html#ChristensenKR07