| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [noun] [prep] such a [adj] period | 13 |
|
| 2 | [noun sg] [prep] such a [adj] period | 10 |
|
| 3 | [noun] [prep] such a short period | 6 |
|
| 4 | [noun] [prep] such a long period | 5 |
|
