
| Rivers. |
| Natural history. |
| Stream ecology. |
| Human ecology. |
| Nature -- Effect of human beings on. |
| Nature observation. |
| Sciences naturelles. |
| Êtres humains -- Influence sur la nature. |
| Nature -- Observation. |
| natural sciences. |
| Ecology. |
| Nature conservation. |
| Nature. |
| Biotic ecology. |
| Travel writing. |
| Informational works. |
| Récits de voyages. |
| Documents d'information. |