| Descriptors | N˚ | % |
| Organization and planning of education | 155 | 16.30 |
| Higher education | 113 | 11.88 |
| Education sector | 113 | 11.88 |
| Teacher preparation | 103 | 10.83 |
| Pedagogy | 96 | 10.09 |
| Basic education | 87 | 9.15 |
| Vocational education | 48 | 5.05 |
| Student assesment | 46 | 4.84 |
| Educational theory and methods | 46 | 4.84 |
| Music and Musicology | 42 | 4.42 |
| Teacher profession and status of teachers | 39 | 4.10 |
| Teacher training and employement | 38 | 4.00 |
| Pedagogical methods | 38 | 4.00 |
| Language teaching | 35 | 3.68 |
| Educational methods | 35 | 3.68 |
| Organization and management of educational institutions | 35 | 3.68 |
| Computer-assisted instruction | 34 | 3.58 |
| Matemathics | 34 | 3.58 |
| Special education | 32 | 3.36 |
| Language and literature | 23 | 16.30 |
| Sociology of education | 21 | 11.88 |