| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [verb] over [art] long period of | 15 |
|
| 2 | [verb] over a long period of | 15 |
|
| 3 | [verb] over a long period of | 15 |
|
| 4 | [vb pp] over [art] long period of | 14 |
|
| 5 | [verb] over [art] long period of | 13 |
|
