Official websites use .gov
A
.gov website belongs to an official
government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you've safely
connected to the .gov website. Share sensitive
information only on official, secure websites.
The top 10 productive countries from 2010 to 2021 (Documents ≥ 3).
| Id | Countries | Documents | Citations |
| 1 | China | 13 | 40 |
| 2 | Spain | 11 | 127 |
| 3 | India | 8 | 107 |
| 4 | United States | 8 | 116 |
| 5 | Turkey | 5 | 10 |
| 6 | Greece | 4 | 43 |
| 7 | Taiwan | 4 | 32 |
| 8 | England | 3 | 95 |
| 9 | Italy | 3 | 43 |
| 10 | Saudi Arabia | 3 | 6 |
