 |
| |||
| combined nitrogen | |||
| fixed nitrogen | |||
|
gebundener Stickstoff : 2 phrases in 2 subjects |
| Environment | 1 |
| Natural resourses and wildlife conservation | 1 |
|
| |||
| combined nitrogen | |||
| fixed nitrogen | |||
|
gebundener Stickstoff : 2 phrases in 2 subjects |
| Environment | 1 |
| Natural resourses and wildlife conservation | 1 |