Topogràfic
H - Social Science
11
L - Education
7
D - World History
6
Q - Science
6
R - Medicine
4
G - Geography, Anthropology, Recreation
3
N - Fine Arts
3
T - Technology
3
K - Law
2
P - Language and Literature
2
Z - Library Science
2
A - Treballs generalss
1
C - Historical Sciences
1
J - Political Science
1
S - Agriculture
1