Número de Clasificación
T - Technology
146
E - United States History
24
P - Language and Literature
23
C - Historical Sciences
20
A - General Works
14
H - Social Science
8
M - Music
8
B - Philosophy, Psychology, Religion
3
N - Fine Arts
3
R - Medicine
3
D - World History
1
G - Geography, Anthropology, Recreation
1
K - Law
1
L - Education
1