Classification
H - Social Science
15
T - Technology
9
D - World History
7
M - Music
6
C - Historical Sciences
5
L - Education
5
P - Language and Literature
3
Q - Science
2
S - Agriculture
2
B - Philosophy, Psychology, Religion
1
E - United States History
1
F - General American History
1
G - Geography, Anthropology, Recreation
1
J - Political Science
1
R - Medicine
1