| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | can be [verb] back through | 5 |
|
| 2 | can [be] [vb pp] back through | 5 |
|
| 3 | can [be] traced back through | 5 |
|
| 4 | can [be] [verb] back through | 5 |
|
| 5 | can [be] [verb] back through | 5 |
|
| 6 | can [be] trace back through | 5 |
|
