| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [verb] back on this | 23 |
|
| 2 | [vb infin] back on this | 12 |
|
| 3 | look back on this | 8 |
|
| 4 | [to-vb] back on this | 5 |
|
| 5 | come back on this | 5 |
|
| 6 | look back on this | 5 |
|
