Topogràfic
H - Social Science
29
Q - Science
5
K - Law
4
A - Treballs generalss
3
B - Filosofia, Psicologia, Religió
3
F - General American History
3
S - Agriculture
3
D - World History
2
T - Technology
2
G - Geography, Anthropology, Recreation
1
J - Political Science
1
L - Education
1
N - Fine Arts
1
U - Military Science
1