Não informado. (1972). Improving human performance quarterly. National Society for Programmed Instruction.
Lua i Stíl Chicago (17ú heag.)Não informado. Improving Human Performance Quarterly. Washington: National Society for Programmed Instruction, 1972.
Lua MLA (8ú heag.)Não informado. Improving Human Performance Quarterly. National Society for Programmed Instruction, 1972.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.