| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [prep] a [adj] period | 2001 |
|
| 2 | [prep] a period [prep] | 1754 |
|
| 3 | a [adj] period [prep] | 1333 |
|
| 4 | [prep] a [adj] [prep] | 1264 |
|
| 5 | [prep] [adj] period [prep] | 362 |
|
