Topogràfic
H - Social Science
689
P - Language and Literature
119
B - Filosofia, Psicologia, Religió
57
K - Law
56
R - Medicine
53
L - Education
33
J - Political Science
27
G - Geography, Anthropology, Recreation
24
F - General American History
17
N - Fine Arts
12
D - World History
11
Q - Science
9
T - Technology
9
U - Military Science
5
C - Historical Sciences
4
S - Agriculture
4
M - Music
3
A - Treballs generalss
1
E - United States History
1