Topogràfic
Q - Science
48
T - Technology
26
H - Social Science
13
R - Medicine
10
D - World History
8
P - Language and Literature
7
G - Geography, Anthropology, Recreation
4
B - Filosofia, Psicologia, Religió
3
S - Agriculture
2
A - Treballs generalss
1
C - Historical Sciences
1
K - Law
1
L - Education
1
M - Music
1
N - Fine Arts
1
U - Military Science
1
Z - Library Science
1