Não informado. (1971). Official Gazette of the United States Patent and Trademark Office. U.S. Department of Commerce.
शिकागो शैली (17वां संस्करण) प्रशस्ति पत्रNão informado. Official Gazette of the United States Patent and Trademark Office. Washington: U.S. Department of Commerce, 1971.
एमएलए (8वां संस्करण) प्रशस्ति पत्रNão informado. Official Gazette of the United States Patent and Trademark Office. U.S. Department of Commerce, 1971.
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