surface density : 44 phrases in 13 subjects |
Astronomy | 1 |
Chemistry | 1 |
Construction | 2 |
Earth sciences | 4 |
Electronics | 1 |
General | 4 |
Industry | 3 |
Magnetics | 3 |
Measuring instruments | 4 |
Microelectronics | 2 |
Optics branch of physics | 2 |
Physics | 9 |
Technology | 8 |