Topogràfic
D - World History
875
P - Language and Literature
641
H - Social Science
516
K - Law
362
L - Education
204
J - Political Science
197
B - Filosofia, Psicologia, Religió
162
N - Fine Arts
124
G - Geography, Anthropology, Recreation
92
F - General American History
62
Q - Science
48
Z - Library Science
40
R - Medicine
39
T - Technology
38
M - Music
29
E - United States History
28
C - Historical Sciences
24
U - Military Science
13
S - Agriculture
11
V - Naval Science
8
A - Treballs generalss
3