Classification
T - Technology
38
L - Education
24
F - General American History
19
P - Language and Literature
15
M - Music
11
B - Philosophy, Psychology, Religion
10
H - Social Science
10
C - Historical Sciences
7
R - Medicine
7
A - General Works
5
N - Fine Arts
4
D - World History
2
Q - Science
2
E - United States History
1
S - Agriculture
1