Não informado. (1971). Official Gazette of the United States Patent and Trademark Office. U.S. Department of Commerce.
Citação do estilo Chicago (17ª ed.)Não informado. Official Gazette of the United States Patent and Trademark Office. Washington: U.S. Department of Commerce, 1971.
Citação MLA (8ª ed.)Não informado. Official Gazette of the United States Patent and Trademark Office. U.S. Department of Commerce, 1971.
Rhybudd: Mae'n bosib nad yw'r dyfyniadau hyn bob amser yn 100% cywir.