Não informado. (1926). Bulletin of the National Association of Secondary School Principals. National Association of Secondary School Principals.
Chicago-viite (17. p.)Não informado. Bulletin of the National Association of Secondary School Principals. Washington: National Association of Secondary School Principals, 1926.
MLA-viite (8. p.)Não informado. Bulletin of the National Association of Secondary School Principals. National Association of Secondary School Principals, 1926.
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