Classification
P - Language and Literature
36,251
H - Social Science
204
S - Agriculture
176
Q - Science
165
B - Philosophy, Psychology, Religion
136
N - Fine Arts
91
D - World History
79
R - Medicine
75
K - Law
56
M - Music
34
L - Education
19
T - Technology
17
J - Political Science
16
G - Geography, Anthropology, Recreation
15
Z - Library Science
7
A - General Works
5
U - Military Science
5
E - United States History
4
C - Historical Sciences
2