1. Ambulatory Surgery Center Association 2012 Ambulatory Surgery Centers: A Positive Trend in Health Care http://www.ascassociation.org/AdvancingSurgicalCare/aboutascs/industryoverview/apositivetrendinhealthcare
2. American Health Planning Association 2012 National Directory http://www.ahpanet.org/national_directory.html
3. American Hospital Association 2012 Trends Affecting Hospitals and Health Systems http://www.aha.org/research/reports/tw/chartbook/index.shtml
4. Free-Standing Ambulatory Surgery Centers and Hospital Surgery Volume;Bian;Inquiry.,2007
5. Centers for Medicare and Medicaid Services 2008 Calendar Year 2008 Revised Ambulatory Surgical Center Payment System http://www.cms.gov/Medicare/Medicare-Fee-for-Service-Payment/ASCPayment/downloads/ASC_QAs_03072008.pdf