Table A1.

Summary of the techniques and methods.

Type of Data	Unit of Analysis	Analytical Methods	Presentations of Results
Abstracts Keywords	Words	Frequency of co-occurrence	1. The number of articles by countries mentioned in the abstract 2. Networks of co-occurrence authors’ keywords 3. Networks of countries by sharing co-authorships data
Abstracts	WoS research domains	Exploratory factor analysis	1. Top 50 research domains
Abstracts	Words	Jaccard’s similarity index	1. Top 50 most frequent co-occurrence terms