1. AHRQ 2013a Cost-to-charge ratio files http://www.hcup-us.ahrq.gov/db/state/costtocharge.jsp
2. AHRQ 2013b Cost-to-charge ratio files: 2011 Central distributor State Inpatient Database User Guide http://www.hcup-us.ahrq.gov/db/state/CCR2011CDUserGuide.pdf
3. AHRQ 2013c Introduction to the HCUP State Inpatient Databases (SID) http://www.hcup-us.ahrq.gov/db/state/siddist/Introduction_to_SID.pdf
4. AHRQ 2014 SID Database Documentation http://www.hcup-us.ahrq.gov/db/state/siddbdocumentation.jsp
5. Arkansas Children's Hospital 2013a Adult congenital heart disease program http://www.archildrens.org/Services/Adult-Congenital-Heart-Disease.aspx