UNSTRUCTURED
The article published on 28 September 2018 is well-written and of interest, but remains several questions that are required for clarifications, such as (1) the number of publications for each year should be noted at the bottom of Figure 1 so that any reader who is interested in reproducing the exponential growth curve(EGC) can compare them each other; (2) the node size in Figure 2 representing the number of author outputs, with larger size indicating more outputs, should be further clarified about the meaning in social network analysis(SNA); and (3) the burst strength and the corresponding temporal bar graphs(TBG) for keywords and citation references in Figures 7 and 9 requires further interpretations. We listed suggestions and references to the article for improvement made in the future relevant studies, including (1)the inflection point(IP) on the EGC; (2) the node size in Figure 2 should equal the weighted publication in comparison to other nodes in the network; and (3) the improved TBG combined with IP and burst strength using the bar size to represent is demonstrated. The three improved visualization of EGC, SNA, and TBG were suggested to the article and the future studies with deeper insights into the bibliometric analysis and make the data easier and clearer to understand.