1. National Hospital Ambulatory Medical Care Survey: 2002 emergency department summary;McCaig,2004
2. Inappropriate emergency department visits;Buesching;Ann Emerg Med,1985
3. Emergency room mis-use by medical assistance patients in a family practice residency;Nelson;J Fam Pract,1979
4. Regular source of ambulatory care and medical care utilization by patients presenting to a public hospital emergency department;Baker;J Am Med Assoc,1994
5. International classification of diseases, 9th revision, clinical modification,1996