"Registration Certificate". United States Patent and Trademark Office. October 6, 1992. Archived from the original on November 6, 2014. Retrieved September 25, 2014. First use 4-5-1991, in commerce 4-5-1991.
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"Registration Certificate". United States Patent and Trademark Office. October 6, 1992. Archived from the original on November 6, 2014. Retrieved September 25, 2014. First use 4-5-1991, in commerce 4-5-1991.