Classification
D - World History
25
R - Medicine
18
H - Social Science
10
F - General American History
8
Q - Science
7
M - Music
5
B - Philosophy, Psychology, Religion
3
J - Political Science
3
A - General Works
2
C - Historical Sciences
2
S - Agriculture
2
L - Education
1
N - Fine Arts
1
P - Language and Literature
1
T - Technology
1
Z - Library Science
1