| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [modal v] [be] referred to | 246 |
|
| 2 | [noun pl] [be] referred to | 205 |
|
| 3 | [noun pl] [modal v] [be] referred | 68 |
|
| 4 | [noun pl] [modal v] [be] to | 36 |
|
