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Types of retrieved documents (2019–2020).
| Document Type | n | % N = 2206 |
|---|---|---|
| Article | 1326 | 60.11 |
| Review | 356 | 16.14 |
| Letter | 271 | 12.28 |
| Note | 116 | 5.26 |
| Editorial material | 115 | 5.21 |
| Short survey | 11 | 0.50 |
| Conference paper | 10 | 0.45 |
| Data article | 1 | 0.05 |
| Total | 2206 | 100 |
