| Audio power amplifier |
9 years, 17 weeks and 3 days |
| Electromagnetic compatibility |
9 years, 17 weeks and 3 days |
| Electromagnetic pulse |
9 years, 17 weeks and 3 days |
| List of natural phenomena |
9 years, 17 weeks and 3 days |
| Gravity |
9 years, 17 weeks and 3 days |
| Atmosphere |
9 years, 17 weeks and 3 days |
| Environment (biophysical) |
9 years, 17 weeks and 3 days |
| Environmental protection |
9 years, 17 weeks and 3 days |
| Environmentalism |
9 years, 17 weeks and 3 days |
| Human-powered transport |
9 years, 17 weeks and 3 days |
| Mode of transport |
9 years, 17 weeks and 3 days |
| Transport |
9 years, 17 weeks and 3 days |
| Renewable energy |
9 years, 17 weeks and 3 days |
| Hydroelectricity |
9 years, 17 weeks and 3 days |
| write ups |
9 years, 17 weeks and 3 days |
