Appendix A

Figure 2: Global publication trends: The number of publications per year for 1967–2025

Figure 3: Collaboration network of countries or regions.

Figure 4. Collaboration network of organizations.

Figure 5: The network of keyword co-occurrences.

Figure 6. Analysis of the keywords in publications : density visualization

Figure 7. The keywords burstness analysis.

Figure 8. The keywords network clustering diagram