| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | a [adj] period of | 842 |
|
| 2 | [det] [adj] period of | 62 |
|
| 3 | [det] a [adj] of | 56 |
|
| 4 | [det] a [adj] period | 33 |
|
| 5 | [det] a period of | 12 |
|
