Klassifikationsnummer
- S - Agriculture 299 results
- Q - Science 262 results
- T - Technology 32 results
- D - World History 31 results
- P - Language and Literature 25 results
- G - Geography, Anthropology, Recreation 22 results
- H - Social Science 19 results
- K - Law 6 results
- R - Medicine 6 results
- C - Historical Sciences 5 results
- E - United States History 5 results
- N - Fine Arts 5 results
- F - General American History 3 results
- V - Naval Science 2 results
- M - Music 1 results
- Z - Library Science 1 results