Topogràfic
R - Medicine
158
T - Technology
90
L - Education
44
H - Social Science
32
P - Language and Literature
22
Q - Science
21
N - Fine Arts
9
K - Law
8
S - Agriculture
7
B - Filosofia, Psicologia, Religió
4
G - Geography, Anthropology, Recreation
3
J - Political Science
3
C - Historical Sciences
2
D - World History
1
E - United States History
1
F - General American History
1
M - Music
1
V - Naval Science
1
Z - Library Science
1