Topogràfic
H - Social Science
79
B - Filosofia, Psicologia, Religió
49
Q - Science
47
R - Medicine
46
L - Education
25
P - Language and Literature
24
K - Law
20
J - Political Science
18
G - Geography, Anthropology, Recreation
16
T - Technology
9
F - General American History
4
U - Military Science
3
Z - Library Science
3
D - World History
2
N - Fine Arts
2
S - Agriculture
2
A - Treballs generalss
1