Keith Cheverst Nigel Davies Keith Mitchell Christos Efstratiou Using Context as a Crystal Ball: Rewards and Pitfalls. 8-11 2001 5 Personal and Ubiquitous Computing 1 http://link.springer.de/link/service/journals/00779/bibs/1005001/10050008.htm db/journals/puc/puc5.html#CheverstDME01