Não informado. (1971). Instructional technology. Girard Associates.
Lua i Stíl Chicago (17ú heag.)Não informado. Instructional Technology. Arlington, NJ: Girard Associates, 1971.
Lua MLA (8ú heag.)Não informado. Instructional Technology. Girard Associates, 1971.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.