Table 1.

Summary of analytical techniques for each data types.

Type of Data	Unit of Analysis	Analytical Methods	Presentations of Results
Terms, Countries	Words	Frequency of co-occurrence	Map of terms co-occurrence clusters
Abstracts	Papers	Latent Dirichlet Allocation	Ten classifications of research topics
WoS classification of research areas	WoS research areas	Frequency of co-occurrence	Dendrogram of research disciplines (WoS classification)