| # | Country | Total Patents | |
|---|---|---|---|
| #1 | Finland | 2 | |
| #2 | Australia | 1 | |
| #3 | Canada | 1 | |
| #4 | Denmark | 1 | |
| #5 | EPO (European Patent Office) | 1 | |
| #6 | Spain | 1 | |
| #7 | Greece | 1 | |
| #8 | Hungary | 1 | |
| #9 | India | 1 | |
| #10 | Portugal | 1 | |
| #11 | United States | 1 | |
| #12 | Yugoslavia (Serbia and Montenegro) | 1 |
| # | Industry | |
|---|---|---|
| #1 | Machines | |
| #2 | Thermal processes |
| # | Technology | |
|---|---|---|
| #1 | Details of furnaces | |
| #2 | Manufacturing processes |
| # | Name | Total Patents |
|---|---|---|
| #1 | Bojkov Dimiter Kostadinov | 7 |
| #2 | Lyutzkanov Stoyan Stefanov | 6 |
| #3 | Lyutzkanov Stoyan S | 2 |
| #4 | Bojkov Dimiter K | 2 |
| #5 | Lyutzkanov Stoyan Stefano | 1 |
| #6 | Lyutzkanov S S | 1 |
| #7 | Stoyan Stefanov L | 1 |
| #8 | Bojkov D K | 1 |