Topogràfic
H - Social Science
996
P - Language and Literature
422
B - Filosofia, Psicologia, Religió
107
R - Medicine
97
K - Law
86
L - Education
68
J - Political Science
36
F - General American History
32
D - World History
31
G - Geography, Anthropology, Recreation
30
N - Fine Arts
29
Q - Science
19
T - Technology
15
E - United States History
9
C - Historical Sciences
8
M - Music
8
U - Military Science
7
A - Treballs generalss
6
S - Agriculture
2