Table 4 The top 20 nationally...

Table 4

The top 20 nationally co-authored countries, data extracted from journals Chum, LLC/DSH, and DHQ, 1966–2017

Rank	Country pair	No. co-authored articles	Rank	Country pair	No. co-authored articles
1	UK–UK	107	11	Italy–Italy	12
2	USA–USA	106	12	China – China	10
3	Canada –Canada	57	13	South Korea–South Korea	8
4	Germany–Germany	47	14	Finland–Finland	6
5	Netherlands –Netherlands	32	15	Norway–Norway	6
6	Australia–Australia	21	16	Japan–Japan	5
7	Spain –Spain	18	17	Singapore–Singapore	5
8	Belgium–Belgium	13	18	Switzerland–Switzerland	5
9	France–France	12	19	Israel–Israel	4
10	Ireland–Ireland	12	20	Sweden–Sweden	4

Rank	Country pair	No. co-authored articles	Rank	Country pair	No. co-authored articles
1	UK–UK	107	11	Italy–Italy	12
2	USA–USA	106	12	China – China	10
3	Canada –Canada	57	13	South Korea–South Korea	8
4	Germany–Germany	47	14	Finland–Finland	6
5	Netherlands –Netherlands	32	15	Norway–Norway	6
6	Australia–Australia	21	16	Japan–Japan	5
7	Spain –Spain	18	17	Singapore–Singapore	5
8	Belgium–Belgium	13	18	Switzerland–Switzerland	5
9	France–France	12	19	Israel–Israel	4
10	Ireland–Ireland	12	20	Sweden–Sweden	4