Não informado. (1977). NASA Conference Publication. National Aeronautics and Space Administration.
शिकागो शैली (17वां संस्करण) प्रशस्ति पत्रNão informado. NASA Conference Publication. Washington: National Aeronautics and Space Administration, 1977.
एमएलए (8वां संस्करण) प्रशस्ति पत्रNão informado. NASA Conference Publication. National Aeronautics and Space Administration, 1977.
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