| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | have been refer to | 125 |
|
| 2 | have be referred to | 110 |
|
| 3 | has be refer to | 55 |
|
| 4 | had be refer to | 25 |
|
| 5 | have be refer to | 21 |
|
| 6 | have be refer to | 12 |
|
| 7 | have be referring to | 12 |
|
| 8 | having be refer to | 5 |
|
