Não informado. (1971). British Journal of Educational Technology. National Council for Educational Technology.
शिकागो शैली (17वां संस्करण) प्रशस्ति पत्रNão informado. British Journal of Educational Technology. London: National Council for Educational Technology, 1971.
एमएलए (8वां संस्करण) प्रशस्ति पत्रNão informado. British Journal of Educational Technology. National Council for Educational Technology, 1971.
चेतावनी: ये उद्धरण हमेशा 100% सटीक नहीं हो सकते हैं.