| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [art] period of about | 44 |
|
| 2 | [art] period of about | 44 |
|
| 3 | a period of about | 42 |
|
| 4 | a period of about | 42 |
|
| 5 | [adj] period of about | 11 |
|
| 6 | [adj] period of about | 6 |
|
| 7 | period of about [num] | 52 |
|
| 8 | period of about [adj] | 52 |
|
| 9 | period of about [art] | 6 |
|
| 10 | period of about [art] | 6 |
|
| 11 | period of about a | 6 |
|
| 12 | period of about a | 6 |
|
| 13 | period of about five | 5 |
|
| 14 | period of about five | 5 |
|
