Número de Clasificación
- H - Social Science 125 results
- D - World History 61 results
- T - Technology 13 results
- J - Political Science 10 results
- L - Education 9 results
- P - Language and Literature 7 results
- N - Fine Arts 6 results
- G - Geography, Anthropology, Recreation 4 results
- R - Medicine 4 results
- C - Historical Sciences 3 results
- K - Law 3 results
- S - Agriculture 3 results
- B - Philosophy, Psychology, Religion 2 results
- F - General American History 1 results
- U - Military Science 1 results
- V - Naval Science 1 results