Classification
P - Language and Literature
30
K - Law
17
H - Social Science
16
T - Technology
8
S - Agriculture
7
J - Political Science
6
F - General American History
5
B - Philosophy, Psychology, Religion
4
D - World History
4
A - General Works
3
C - Historical Sciences
3
R - Medicine
3
M - Music
2
E - United States History
1