HD - Industries, Land Use, Labor 941
H - Social Science 404
HF - Commerce 383
HE - Transportation and Communications 170
HC - Economic History and Conditions 145
HQ - Family, Marriage, Women 118
HG - Finance 73
HT - Communities, Classes, Races 69
HA - Statistics 51
HN - Social History and Conditions 50
HB - Economic Theory and Demography 37
HJ - Public Finance 35
HV - Social Pathology, Criminology 35
HM - Sociology 21
HS - Societies 1