| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | have refer to [prep] | 7 |
|
| 2 | have referred [prep] [prep] | 7 |
|
| 3 | have refer to [prep] | 7 |
|
| 4 | have refer [prep] [prep] | 7 |
|
| 5 | have refer [prep] as | 6 |
|
