Topogràfic
T - Technology
12
H - Social Science
9
D - World History
7
P - Language and Literature
6
Q - Science
5
K - Law
4
B - Filosofia, Psicologia, Religió
3
E - United States History
3
G - Geography, Anthropology, Recreation
3
C - Historical Sciences
2
F - General American History
2
N - Fine Arts
2
S - Agriculture
2
Z - Library Science
2
A - Treballs generalss
1
J - Political Science
1
L - Education
1
R - Medicine
1