1. National Ambulatory Medicare Care Survey: 2001 Summary;Cherry,2003
2. National Hospital Ambulatory Medical Care Survey: 2001 Outpatient Department Summary;Hing,2003
3. National Hospital Ambulatory Medical Care Survey: 2001 Emergency Department Summary;McCaig,2003
4. International Classification of Diseases, Ninth Revision, Clinical Modification,2003
5. 2002 National Hospital Discharge Survey;DeFrances,2004