APA
(1921). Housing and equipment of kindergartens. Washington, USA: U.S. Government Printing Office.
Chicago
1921. Housing and equipment of kindergartens. Washington, USA: U.S. Government Printing Office.
Harvard
(1921). Housing and equipment of kindergartens. Washington, USA: U.S. Government Printing Office.
MLA
Housing and equipment of kindergartens. Washington, USA: U.S. Government Printing Office. 1921.
