Letter	Sub heading
A	Social sciences general (inc. Economics)
B	History of economic thought
C	Treatises, text books, general works
D	Aspects of economic theory
F	Money and banking
G	Commentaries on economic and financial policy
H	International economics
J	Finance
L	Economics of specific countries and regions
N	Industry
R	Mathematical economics and statistics
T	Social conditions, problems and services
V	Labour economics
Y	Economic systems, politics and economics