3.2.1. Group 1—Subclusters

10 subclusters have been found (Figure 17), five of which boast a significant number of publications (Table 4). The remaining groups are relatively small with less than 200 publications and 1778 citation networks.

**Figure 17.** Group 1-subclusters citation network.


**Table 4.** The most important subclusters from group 1.
