Classification
P - Language and Literature
63
G - Geography, Anthropology, Recreation
54
R - Medicine
46
D - World History
39
B - Philosophy, Psychology, Religion
31
T - Technology
24
Q - Science
17
C - Historical Sciences
14
M - Music
11
A - General Works
7
S - Agriculture
7
E - United States History
5
H - Social Science
4
K - Law
2
F - General American History
1