Não informado. (1964). Programmed learning. Association for Programmed Learning.
Lua i Stíl Chicago (17ú heag.)Não informado. Programmed Learning. London: Association for Programmed Learning, 1964.
Lua MLA (8ú heag.)Não informado. Programmed Learning. Association for Programmed Learning, 1964.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.