1. Patient Centered Primary Care Implementation Work Group 2012 http://www.va.gov/PrimaryCare/docs/pcmh_ConceptPaper.doc
2. American Academy of Family Physicians (AAFP) American Academy of Pediatrics (AAP) American College of Physicians (ACP) American Osteopathic Association (AOA) 2007 http://www.aafp.org/dam/AAFP/documents/practice_management/pcmh/initiatives/PCMHJoint.pdf
3. US Department of Veterans Affairs 2012 http://www.va.gov/primarycare/pcmh/
4. Veterans Health Administration Research & Development 2012 http://www.research.va.gov/resources/pubs/cboc.cfm
5. Osteoarthritis: new insights. Part 1: the disease and its risk factors;Felson;Ann Intern Med,2000