Assignee
Inventors
- Orhideya B. Zabunova (4 patents)
- Hristo B. Zvetanov (1 patents)
- Lyudmila V. Petrova (1 patents)
- Vaska A. Ognyanova (1 patents)
- Milka P. Nikolova (3 patents)
- Georgi L. Tanev (1 patents)
- Nedyalka S. Ivanova (3 patents)
US Patent 4704468 · Granted Nov 3, 1987