Classification
R - Medicine
31,254
B - Philosophy, Psychology, Religion
18,425
D - World History
11,221
A - General Works
7,042
Q - Science
6,923
H - Social Science
3,571
P - Language and Literature
2,945
T - Technology
2,632
F - General American History
2,455
S - Agriculture
1,314
G - Geography, Anthropology, Recreation
1,111
C - Historical Sciences
996
E - United States History
657
Z - Library Science
637
L - Education
513
M - Music
457
K - Law
441
J - Political Science
376
N - Fine Arts
260
U - Military Science
194
V - Naval Science
74