Não informado. (1957). Electrical equipment news. Southam Business Publications.
शिकागो शैली (17वां संस्करण) प्रशस्ति पत्रNão informado. Electrical Equipment News. Toronto, Canada: Southam Business Publications, 1957.
एमएलए (8वां संस्करण) प्रशस्ति पत्रNão informado. Electrical Equipment News. Southam Business Publications, 1957.
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