Não informado. (1980). Principal. National Association of Elementary School Principals.
Lua i Stíl Chicago (17ú heag.)Não informado. Principal. Arlington, Va: National Association of Elementary School Principals, 1980.
Lua MLA (8ú heag.)Não informado. Principal. National Association of Elementary School Principals, 1980.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.