Table 3 Systematic reviews of which more than ten included references were not retrieved in Google Scholar; performance of improved searches
| Number of included references | Number of includes retrieved by | |||
|---|---|---|---|---|
| Authors’ search | Improved search #1 | Improved search #2 | ||
| Hasani | 78 | 26 | 26 | 37 |
| Novak | 30 | 10 | 12 | 12 |
| Verhoeven | 89 | 72 | 75 | 72 |
| Navarese | 17 | 6 | 13 | 16 |
| Belsey | 20 | 10 | 15 | 16 |
| 234 | 124 (53%) | 141 (60%) | 154 (66%) | |