A – General Works
B – Philosophy, Psychology, Religion
C – Auxiliary Sciences of History
D – History (GENERAL) & History of Europe
E – History, America
F – History, America
G – Geography, Anthropology, Recreation
H – Social Sciences
J – Political Science
K – Law
L – Education
M – Music
N – Fine Arts
P – Language and Literature
Q – Science
R – Medicine
S – Agriculture
T – Technology
U – Military Science
V – Naval Science
Z – Bibliography, Library Science, Information Resources (General)