| Subject area | Documents |
|---|---|
| Environmental science | 101 |
| Social sciences | 85 |
| Economics, econometrics and finance | 48 |
| Energy | 44 |
| Business, management and accounting | 32 |
| Computer science | 25 |
| Engineering | 20 |
| Medicine | 8 |
| Multidisciplinary | 7 |
| Agricultural and biological sciences | 6 |