Número de Clasificación
T - Technology
532
M - Music
175
C - Historical Sciences
73
S - Agriculture
70
H - Social Science
50
L - Education
40
A - General Works
14
G - Geography, Anthropology, Recreation
8
R - Medicine
6
B - Philosophy, Psychology, Religion
4
P - Language and Literature
4
D - World History
3
F - General American History
2
N - Fine Arts
2