Não informado. (2002). Principal Leadership. National Association of Secondary School Principals.
Chicago Style (17. basım) AtıfNão informado. Principal Leadership. Reston, Va: National Association of Secondary School Principals, 2002.
MLA (8th ed.) AtıfNão informado. Principal Leadership. National Association of Secondary School Principals, 2002.
Uyarı: Bu alıntı herzaman %100 doğru olmayabilir..