Topogràfic
H - Social Science
4,010
R - Medicine
2,310
Q - Science
1,696
T - Technology
1,439
L - Education
483
P - Language and Literature
482
K - Law
462
B - Filosofia, Psicologia, Religió
343
G - Geography, Anthropology, Recreation
327
S - Agriculture
287
D - World History
273
J - Political Science
196
Z - Library Science
194
A - Treballs generalss
148
N - Fine Arts
105
E - United States History
98
U - Military Science
87
F - General American History
86
M - Music
76
C - Historical Sciences
40
V - Naval Science
27