| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | source of [noun] [prep] [art] | 428 |
|
| 2 | [noun] of energy [prep] [art] | 89 |
|
| 3 | source [prep] energy [prep] [art] | 11 |
|
| 4 | source of energy [prep] [art] | 11 |
|
