| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | believe to have been [verb] [prep] | 83 |
|
| 2 | believe to have been [vb pp] [prep] | 80 |
|
| 3 | [verb] to have been used [prep] | 30 |
|
| 4 | believe have been used [prep] | 6 |
|
| 5 | believe [verb] been used [prep] | 6 |
|
| 6 | believe to have been use [prep] | 5 |
|
| 7 | believe [to-vb] been used [prep] | 5 |
|
| 8 | believe to have be used [prep] | 5 |
|
| 9 | believe to have [been] used [prep] | 5 |
|
| 10 | believe to have [be] used [prep] | 5 |
|
