Table 4.

Citation characteristics of clusters based on co-authorship of countries according to the authors’ affiliations

Cluster	# Items	Countries	D	TC	AC	ANC
1 (blue)	10	Singapore, Italy, Austria, Ireland, Sweden, Spain, Germany, Belgium, Netherlands and France	147	8183	54.20 ± 17.42	1.79 ± 0.43
2 (green)	9	New Zealand, Kenya, Brazil, Pakistan, China, Canada, Malaysia, Bangladesh, and Thailand	117	4251	38.12 ± 30.00	1.25 ± 0.63
3 (red)	9	United Arab Emirates, Denmark, USA, Japan, India, England, Scotland, Norway, and Nepal	191	6979	26.06 ± 16.17	1.14 ± 0.48
4 (yellow)	4	South Africa, Mexico, Switzerland, and Nigeria	58	2922	48.17 ± 10.17	1.22 ± 0.25
5 (pink)	2	Australia and South Korea	55	2024	26.45 ± 17.89	0.88 ± 0.55

D, number of documents; TC, total citations; AC, average number of citations per year; ANC, average normalized citations