Classification
Q - Science
35
T - Technology
34
S - Agriculture
22
H - Social Science
20
R - Medicine
12
D - World History
8
L - Education
7
A - General Works
6
P - Language and Literature
6
G - Geography, Anthropology, Recreation
5
U - Military Science
5
K - Law
4
Z - Library Science
3
B - Philosophy, Psychology, Religion
2
J - Political Science
2
C - Historical Sciences
1
M - Music
1