7Bureau of Labor Statistics, U.S.Department of Labor (2006).May 2005 state occupational employment and wage: Washington, D.C.
8OECD thematic review of education and care policy background report, 2003
9Early childhood education in the United States: Using Illinois as a case study. In L. K. S. Chan & E. J. .Mellor (Eds.), International Developments in Early Childhood Services. New York: Peter Lang, 2002
