HD - Industries, Land Use, Labor 9,475
HF - Commerce 4,355
HG - Finance 3,495
HC - Economic History and Conditions 3,267
HB - Economic Theory and Demography 1,972
HJ - Public Finance 581
HE - Transportation and Communications 560
HM - Sociology 424
HV - Social Pathology, Criminology 379
HQ - Family, Marriage, Women 215
HT - Communities, Classes, Races 180
HN - Social History and Conditions 165
H - Social Science 100
HX - Socialism, Communism, Anarchism 36
HA - Statistics 29
HS - Societies 1