Classification
S - Agriculture
175
Q - Science
130
T - Technology
79
R - Medicine
50
H - Social Science
43
G - Geography, Anthropology, Recreation
20
L - Education
19
M - Music
15
A - General Works
14
N - Fine Arts
12
B - Philosophy, Psychology, Religion
6
U - Military Science
6
Z - Library Science
5
C - Historical Sciences
4
P - Language and Literature
4
D - World History
3
J - Political Science
2