Fig. 3
![Fig. 3](http://media.springernature.com/full/springer-static/image/art%3A10.1186%2Fs41016-021-00264-y/MediaObjects/41016_2021_264_Fig3_HTML.png)
The network of the articles co-cited by retrieved articles from China. The size of the nodes represents the co-cited times of one article. The articles that areco-cited by the same article are connected with lines. The thickness of the lines reflects the co-cited counts. All the articles belonging to one cluster are covered by regions with different colors. Time is reflected by different colors