Não informado. Visual education. National Committee for Visual Aids in Education.
शिकागो शैली (17वां संस्करण) प्रशस्ति पत्रNão informado. Visual Education. London: National Committee for Visual Aids in Education.
एमएलए (8वां संस्करण) प्रशस्ति पत्रNão informado. Visual Education. National Committee for Visual Aids in Education.
चेतावनी: ये उद्धरण हमेशा 100% सटीक नहीं हो सकते हैं.