Handbook on the use of the U.S. patent classification system.
Contributors: United States. Patent and Trademark Office. Search and Information Resources.
Publisher: U.S. Patent and Trademark Office, Search and Information Resources
Published: 1997
Place of publication: [Washington, D.C.]
Language: eng
Number of pages: 46
Subjects: Patents -- United States -- Classification.; Patent searching.
Notes: "Revised February 1997."

Includes index.