APA

United States, . (1991). United States Patent and Trademark Office. Washington, D.C. (ICPK, Suite 700, Box 171, Washington 20231): The Office.

Chicago

United States, . 1991. United States Patent and Trademark Office. Washington, D.C. (ICPK, Suite 700, Box 171, Washington 20231): The Office.

Harvard

United States, . (1991). United States Patent and Trademark Office. Washington, D.C. (ICPK, Suite 700, Box 171, Washington 20231): The Office.

MLA

United States, . United States Patent and Trademark Office. Washington, D.C. (ICPK, Suite 700, Box 171, Washington 20231): The Office. 1991.