Não informado. (1974). Communication and broadcasting. Marconi Communication Systems.
शिकागो शैली (17वां संस्करण) प्रशस्ति पत्रNão informado. Communication and Broadcasting. Chelmsford, Inglaterra: Marconi Communication Systems, 1974.
एमएलए (8वां संस्करण) प्रशस्ति पत्रNão informado. Communication and Broadcasting. Marconi Communication Systems, 1974.
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