| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [prep] [art] longer period of | 12 |
|
| 2 | [prep] a longer period of | 12 |
|
| 3 | [prep] [art] longer period of | 12 |
|
| 4 | [prep] a longer period of | 12 |
|
| 5 | over [art] longer period of | 7 |
|
| 6 | over [art] longer period of | 7 |
|
