Número de Clasificación
T - Technology
88
A - General Works
42
L - Education
36
B - Philosophy, Psychology, Religion
26
K - Law
18
N - Fine Arts
16
C - Historical Sciences
14
E - United States History
10
M - Music
10
F - General American History
3
H - Social Science
3
P - Language and Literature
3
D - World History
2
G - Geography, Anthropology, Recreation
1
Q - Science
1
S - Agriculture
1