Table 1.
Types of retrieved documents
| Type of document | Frequency | % N = 8619 |
|---|---|---|
| Article | 6633 | 77.0 |
| Review | 984 | 11.4 |
| Letter | 304 | 3.5 |
| Note | 258 | 3.0 |
| Conference Paper | 192 | 2.2 |
| Editorial | 141 | 1.6 |
| Short Survey | 107 | 1.2 |
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