1. National Health Expenditures Highlights 2013 http://www.cms.gov/Research-Statistics-Data-and-Systems/Statistics-Trends-and-Reports/NationalHealthExpendData/NationalHealthAccountsHistorical.html
2. Oral health America's national oral health report card;Oral Health America;Dent Assist,2002
3. The Pew Charitable Trusts The Pew Center on the States The cost of delay: state dental policies fail 1 in 5 children 2010
4. NCHS data brief, no 96;Dye,2012