National Association of Secondary School Principals (U.S.). (1981). Schools in the middle. The Association.
Chicago-referens (17:e uppl.)National Association of Secondary School Principals (U.S.). Schools in the Middle. Reston, Va.: The Association, 1981.
MLA-referens (9:e uppl.)National Association of Secondary School Principals (U.S.). Schools in the Middle. The Association, 1981.
Varning: dessa hänvisningar är inte alltid fullständigt riktiga.