TY  - BOOK
ED  - United States
TI  - Index to the U.S. patent classification
PB  - U.S. Dept. of Commerce, Patent and Trademark Office
KW  - United States
KW  - Patent and Trademark Office
KW  - Office of Documentation Planning and Support
KW  - Manual of classification
KW  - Local
KW  - Patents
KW  - Classification
N1  - Description based on: 1980
UR  - http://purl.access.gpo.gov/GPO/LPS692299
ER  -