 |
| |||
| low coal; small coal; thin coal | |||
| low-coal seam | |||
| тонкий угольный пласт: 9 do fraz, 3 tematyki |
| Geologia | 5 |
| Górnictwo | 3 |
| Technika i technologia | 1 |
|
| |||
| low coal; small coal; thin coal | |||
| low-coal seam | |||
| тонкий угольный пласт: 9 do fraz, 3 tematyki |
| Geologia | 5 |
| Górnictwo | 3 |
| Technika i technologia | 1 |