| Keyword | CPC | PCC | Volume | Score | Length of keyword |
|---|---|---|---|---|---|
| primary and secondary historical sources | 1.12 | 0.3 | 1011 | 81 | 40 |
| primary | 0.55 | 0.1 | 1854 | 20 | 7 |
| and | 0.8 | 0.8 | 148 | 95 | 3 |
| secondary | 1.4 | 0.2 | 1175 | 72 | 9 |
| historical | 0.39 | 0.4 | 9431 | 21 | 10 |
| sources | 1.25 | 0.3 | 976 | 64 | 7 |
| Keyword | CPC | PCC | Volume | Score |
|---|---|---|---|---|
| primary and secondary historical sources | 0.11 | 0.4 | 6931 | 89 |
