| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [vb pp] to refer to [art] | 57 |
|
| 2 | [vb pp] refer to the | 41 |
|
| 3 | used refer to [art] | 35 |
|
| 4 | [vb pp] refer to a | 15 |
|
| 5 | [vb pp] refer to an | 7 |
|
| 6 | understood refer to [art] | 5 |
|
