| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [prep] [art] period of | 2328 |
|
| 2 | [prep] [art] long period | 413 |
|
| 3 | [art] long period of | 240 |
|
| 4 | [prep] [art] long of | 8 |
|
