1. Pfunter AW Stocks C Most frequent procedures performed in US hospitals 2010 http://hcup-us.ahrq.gov/reports/statbriefs/sb149.pdf
2. US Department of Health and Human Services The 2011 national blood collection and utilization report 2012 Washington, DC Department of Health and Human Services
3. United States Food and Drug Administration Fatalities reported to FDA following blood collection and transfusion: annual summary for fiscal year 2013 2014 http://www.fda.gov/BiologicsBloodVaccines/SafetyAvailability/ReportaProblem/TransfusionDonationFatalities/ucm391574.htm
4. Transfusion rates vary significantly amongst Canadian medical centres;Hutton;Can J Anaesth,2005
5. Variation in use of blood transfusion in coronary artery bypass graft surgery;Bennett-Guerrero;JAMA,2010