Topogràfic
H - Social Science
782
K - Law
581
F - General American History
443
J - Political Science
211
B - Filosofia, Psicologia, Religió
200
L - Education
199
P - Language and Literature
196
G - Geography, Anthropology, Recreation
101
N - Fine Arts
87
R - Medicine
84
Q - Science
74
T - Technology
50
M - Music
33
S - Agriculture
26
U - Military Science
25
Z - Library Science
20
A - Treballs generalss
19
C - Historical Sciences
7
D - World History
6
E - United States History
4