Não informado. (2002). Principal Leadership. National Association of Secondary School Principals.
Citação do estilo Chicago (17ª ed.)Não informado. Principal Leadership. Reston, Va: National Association of Secondary School Principals, 2002.
Citação MLA (8ª ed.)Não informado. Principal Leadership. National Association of Secondary School Principals, 2002.
Предупреждение: эти цитированмия не могут быть всегда правильны на 100%.