APA (7th ed.) Citation

U.S. Customs Service. (1993). How to obtain copyright, trademark, and patent protection from the U.S. Customs Service (Revised Apr. 1993.). The Service.

Chicago Style (17th ed.) Citation

U.S. Customs Service. How to Obtain Copyright, Trademark, and Patent Protection from the U.S. Customs Service. Revised Apr. 1993. [Washington, D.C.?]: The Service, 1993.

MLA (9th ed.) Citation

U.S. Customs Service. How to Obtain Copyright, Trademark, and Patent Protection from the U.S. Customs Service. Revised Apr. 1993. The Service, 1993.