ha1-4737 statistics
hb1-3840 economic therory. demography
hc10-1085 economic history and conditons
hd28-9999 industries. land use. labor
he1-9990 transportation and communications
hf1-6182 commerce
hg1-9999 finance
hj9-9940 public finace
hm(1)-1281 sociology
hn1-995 social history and conditions. social problems. social reform
ht51-1595 communities. classes. races
hv1-9960 social pathology. social and public welfare. criminology
hx1-970.7 socialism. communism. anarchism.