Table 9.
Analysis of keyword clusters.
| Occurrence | Average publication year | Average citations | |
|---|---|---|---|
| Cluster 1 | 27.6 | 2016.8 | 16.7 |
| Cluster 2 | 68.6 | 2017.3 | 16.4 |
| Cluster 3 | 31.8 | 2016.5 | 17.7 |
| Cluster 4 | 46.5 | 2015.2 | 22.8 |
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