Classification
Q - Science
90
T - Technology
69
S - Agriculture
27
H - Social Science
25
R - Medicine
17
Z - Library Science
6
D - World History
5
G - Geography, Anthropology, Recreation
4
P - Language and Literature
4
A - General Works
3
K - Law
3
B - Philosophy, Psychology, Religion
2
C - Historical Sciences
2
N - Fine Arts
2
L - Education
1
M - Music
1