| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | a [adj] period of | 889 |
|
| 2 | and a period of | 32 |
|
| 3 | and [adj] period of | 21 |
|
| 4 | and a [adj] period | 19 |
|
| 5 | and a [adj] of | 7 |
|
