Table 1.

Country distribution (top 10).

Rank	Country (region)	Freq.	Total citation frequency	The average cited frequency	H-index
1	China	620	10828	17.46	73
2	USA	434	22377	51.56	48
3	Germany	161	9366	58.17	45
4	Japan	107	4264	39.85	25
5	France	62	2982	48.10	25
6	Australia	51	3010	59.02	22
7	UK	50	3752	75.04	20
8	Canada	46	2092	45.48	18
9	Italy	44	1539	34.98	17
10	Russia	35	1640	46.86	15