HD - Industries, Land Use, Labor 766,119
HC - Economic History and Conditions 395,222
HV - Social Pathology, Criminology 320,743
HQ - Family, Marriage, Women 276,023
HF - Commerce 259,147
HB - Economic Theory and Demography 231,927
HG - Finance 213,126
HN - Social History and Conditions 128,447
HE - Transportation and Communications 114,194
HM - Sociology 113,899
HT - Communities, Classes, Races 113,574
HX - Socialism, Communism, Anarchism 85,395
HJ - Public Finance 83,153
HA - Statistics 57,859
H - Social Science 43,486
HS - Societies 15,895
F - General American History 3
B - Philosophy 2
E - United States History 2
N - Visual Arts 2
DP - Spain, Portugal 1
NC - Drawing, Design, Illustration 1
PS - American Literature 1