1. The emergency room physician and the changing pattern of medical care;Shortliffe;N Engl J Med,1988
2. Hospital Statistics 1991-1992;American Hospital Association,1992
3. Compliance with emergency department patient referral;Vukmir;Ann Emerg Med,1990
4. States, hospitals aim to cut costly emergency department visits;Koska;Hospitals,1988
5. The 1980 patient urgency study: Further analysis of the data;Guterman;Ann Emerg Med,1985