Izobretatelskoto, ratsionalizatorskoto i patentnoto delo v NR Bŭlgari︠a︡
Edition: (2. ... )
Publisher: ...
Published: 1971
Language: bul
Number of pages: 317
Subjects: Inventions; Patents
Notes: At head of title: ...

First ed., 1966, has title: ...

Includes bibliographical references.