| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [adv] [prep] [adj] period of | 46 |
|
| 2 | [adv] [prep] long [noun] of | 30 |
|
| 3 | [adv] [prep] long period [prep] | 14 |
|
| 4 | [adv] [prep] long period of | 12 |
|
