Classification
D - World History
51
H - Social Science
50
Q - Science
32
F - General American History
31
T - Technology
26
S - Agriculture
18
K - Law
17
C - Historical Sciences
13
J - Political Science
12
R - Medicine
8
E - United States History
6
M - Music
5
G - Geography, Anthropology, Recreation
4
L - Education
4
U - Military Science
4
B - Philosophy, Psychology, Religion
2
P - Language and Literature
2
Z - Library Science
1