Topogràfic
H - Social Science
27,882
P - Language and Literature
20,283
R - Medicine
12,352
L - Education
11,869
Q - Science
11,739
B - Filosofia, Psicologia, Religió
10,320
T - Technology
10,219
K - Law
10,044
J - Political Science
5,912
S - Agriculture
5,344
F - General American History
4,630
G - Geography, Anthropology, Recreation
4,296
D - World History
4,065
N - Fine Arts
2,681
Z - Library Science
1,650
A - Treballs generalss
1,127
C - Historical Sciences
876
M - Music
755
E - United States History
522
U - Military Science
329
V - Naval Science
76