| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [art] [adv] long period of | 18 |
|
| 2 | a [adv] long period of | 17 |
|
| 3 | [art] very long period of | 8 |
|
| 4 | [art] [adv] longer period of | 5 |
|
| 5 | the [adv] long period of | 5 |
|
