Classification
Q - Science
15
D - World History
8
H - Social Science
8
T - Technology
6
S - Agriculture
3
B - Philosophy, Psychology, Religion
2
J - Political Science
2
L - Education
2
P - Language and Literature
2
C - Historical Sciences
1
F - General American History
1
G - Geography, Anthropology, Recreation
1
K - Law
1
U - Military Science
1
Z - Library Science
1