Development and use of patent classification systems
Connor, John T
Development and use of patent classification systems - Washington, D. C.: Patent Office United States of America, 1966 - 201p.
Classification systems
Patent classification system
D 025.4:608.3 / K6
Development and use of patent classification systems - Washington, D. C.: Patent Office United States of America, 1966 - 201p.
Classification systems
Patent classification system
D 025.4:608.3 / K6