1. US Census Bureau. The older population in the United States: 2010-2050 population estimates and projections. Available at: https://www.census.gov/prod/2010pubs/p25-1138.pdf. Accessed March 29, 2014.
2. Department of Health and Human Services, Administration on Aging. A profile of older Americans. Available at: http://www.aoa.gov/Aging_Statistics/Profile/2013/docs/2013_Profile.pdf. Accessed July 10, 2014.
3. The Henry J. Kaiser Family Foundation. Healthcare spending in the United States. Available at: http://kff.org/health-costs/issue-brief/snapshots-health-care-spending-in-the-united-states-selected-oecd-countries. Accessed July 10, 2014.
4. Improving the completion of advance directives in the primary care setting: a randomized control trial;Helman;Am J Med,2004
5. Wenger NS, Shugarman LR, Wilkinson A. Advance directives and advance care planning: Report to Congress. RAND Corporation Report to United States Department of Health and Human Services; 2008. Available at: http://.aspe.hhs.gov/daltcp/reports/2008/ADCongRpt-B.pdf. Accessed December 1, 2013.