Não informado. (1926). Bulletin of the National Association of Secondary School Principals. National Association of Secondary School Principals.
Čikaški stil citiranja (17. izdanje)Não informado. Bulletin of the National Association of Secondary School Principals. Washington: National Association of Secondary School Principals, 1926.
MLA način citiranja (8. izdanje)Não informado. Bulletin of the National Association of Secondary School Principals. National Association of Secondary School Principals, 1926.
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