APA (7th ed.) Citation

United States. Patent and Trademark Office & United States. Patent and Trademark Office. Office of Electronic Information Products and Services. Classification orders index. U.S. Dept. of Commerce, Patent and Trademark Office, Office of Electronic Information Products and Services.

Chicago Style (17th ed.) Citation

United States. Patent and Trademark Office and United States. Patent and Trademark Office. Office of Electronic Information Products and Services. Classification Orders Index. [Washington, D.C.]: U.S. Dept. of Commerce, Patent and Trademark Office, Office of Electronic Information Products and Services.

MLA (9th ed.) Citation

United States. Patent and Trademark Office and United States. Patent and Trademark Office. Office of Electronic Information Products and Services. Classification Orders Index. U.S. Dept. of Commerce, Patent and Trademark Office, Office of Electronic Information Products and Services.