Topogràfic
B - Filosofia, Psicologia, Religió
100
H - Social Science
48
L - Education
25
Q - Science
12
G - Geography, Anthropology, Recreation
5
P - Language and Literature
5
N - Fine Arts
3
T - Technology
3
F - General American History
2
R - Medicine
2
Z - Library Science
2
A - Treballs generalss
1
J - Political Science
1