Não informado. (1974). Special report. National Research Council, Transportation Research Board.
शिकागो शैली (17वां संस्करण) प्रशस्ति पत्रNão informado. Special Report. Washington: National Research Council, Transportation Research Board, 1974.
एमएलए (8वां संस्करण) प्रशस्ति पत्रNão informado. Special Report. National Research Council, Transportation Research Board, 1974.
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