Signum
D - World History
12 883
H - Social Science
7 302
G - Geography, Anthropology, Recreation
2 835
P - Language and Literature
2 585
B - Philosophy, Psychology, Religion
1 797
N - Fine Arts
1 482
J - Political Science
1 219
Z - Library Science
1 052
Q - Science
813
T - Technology
708
K - Law
701
L - Education
598
S - Agriculture
472
R - Medicine
447
M - Music
443
A - General Works
430
C - Historical Sciences
382
U - Military Science
335
E - United States History
163
F - General American History
82
V - Naval Science
76