Topogràfic
H - Social Science
70
T - Technology
37
P - Language and Literature
19
L - Education
12
K - Law
11
Z - Library Science
6
Q - Science
5
A - Treballs generalss
3
B - Filosofia, Psicologia, Religió
2
G - Geography, Anthropology, Recreation
2
J - Political Science
2
N - Fine Arts
2
R - Medicine
1
S - Agriculture
1