Topogràfic
K - Law
31
H - Social Science
29
D - World History
26
A - Treballs generalss
22
Q - Science
17
F - General American History
11
B - Filosofia, Psicologia, Religió
10
C - Historical Sciences
8
N - Fine Arts
8
Z - Library Science
8
M - Music
4
G - Geography, Anthropology, Recreation
3
S - Agriculture
1