| Keyword | CPC | PCC | Volume | Score |
|---|---|---|---|---|
| farmer in the sky robert a heinlein | 0.49 | 0.6 | 5816 | 71 |
| robert a. heinlein - farmer in the sky | 0.59 | 0.3 | 8103 | 38 |
| robert heinlein orphans in the sky | 0.5 | 0.8 | 7007 | 65 |
| robert heinlein tunnel in the sky | 0.38 | 0.7 | 2429 | 77 |
| farmer in the sky | 0.71 | 0.7 | 3242 | 81 |
| farmer in the sky pdf | 0.02 | 0.1 | 476 | 80 |
| robert heinlein to the stars | 2 | 1 | 8211 | 93 |
| robert a heinlein friday | 0.1 | 0.9 | 8730 | 16 |
| robert heinlein time for the stars | 1.65 | 0.5 | 8594 | 91 |
| heinlein orphans of the sky | 0.7 | 0.8 | 7710 | 93 |
| earth wind by robert heinlein | 0.61 | 0.9 | 4927 | 95 |
