Fig. 4

A The cooperation network map of institutions generated by CiteSpace. Each node represents an institution and the node size is proportional to the number of publications by that institution. The node with the highest BC value (≥ 0.1) are usually known as hubs nodes that usually marked with purple rings. The connecting line between nodes indicates the cooperation relationship, and the value of link strength is also displayed between lines. B The total number of publications, H-index, and average citations per item of top 10 productive authors in this field. C The cooperation network map of productive authors generated by CiteSpace. The graphical explanations are the same as in A. D Authors co-citation analysis by VOSviewer. Each node represents a different author, and the node size is proportional to the quantity of citations. The thickness of the connecting line between nodes indicates link strength of a co-citation relationship, which could be weighted by a quantitative indicator that is TLS