索引号
P - Language and Literature
17
H - Social Science
10
S - Agriculture
9
Q - Science
8
G - Geography, Anthropology, Recreation
7
L - Education
5
R - Medicine
5
T - Technology
5
B - Philosophy, Psychology, Religion
3
D - World History
3
N - Fine Arts
3
A - General Works
2
F - General American History
2
K - Law
2
E - United States History
1
J - Political Science
1
M - Music
1
Z - Library Science
1