Número de Clasificación
P - Language and Literature
226
C - Historical Sciences
78
T - Technology
71
S - Agriculture
70
M - Music
13
E - United States History
12
A - General Works
10
B - Philosophy, Psychology, Religion
6
H - Social Science
5
G - Geography, Anthropology, Recreation
3
J - Political Science
2
R - Medicine
2
D - World History
1
K - Law
1
L - Education
1