Classification
T - Technology
45
Q - Science
34
B - Philosophy, Psychology, Religion
13
A - General Works
11
R - Medicine
10
D - World History
9
E - United States History
9
M - Music
9
K - Law
6
C - Historical Sciences
5
P - Language and Literature
5
Z - Library Science
5
H - Social Science
4
U - Military Science
2
J - Political Science
1