U.S. Office of Education. (1906). Bulletin. United States. Government Printing Office.
Chicago-referens (17:e uppl.)U.S. Office of Education. Bulletin. Washington: United States. Government Printing Office, 1906.
MLA-referens (9:e uppl.)U.S. Office of Education. Bulletin. United States. Government Printing Office, 1906.
Varning: dessa hänvisningar är inte alltid fullständigt riktiga.