1. The condition of education 2006;Wirt,2006
2. Characteristics of private schools in the United States: results from the 2001-2002 private school Universe Survey;Broughman,2004
3. Overview of public elementary and secondary schools and districts: school year 2001–02;Hoffman,2003
4. School facilities: condition of America's schools;US General Accounting Office,1995
5. School facilities: America's schools report differing conditions;US General Accounting Office,1996