 |
| |||
| ambient radiation | |||
| background | |||
| natural radiation background; radiation background | |||
| background radiation; natural background radiation | |||
| Untergrundstrahlung: 13 phrases in 4 subjects |
| High energy physics | 2 |
| Natural resourses and wildlife conservation | 1 |
| Nuclear physics | 9 |
| Optics branch of physics | 1 |