HD - Industries, Land Use, Labor 735,096
HC - Economic History and Conditions 378,916
HV - Social Pathology, Criminology 306,161
HQ - Family, Marriage, Women 262,083
HF - Commerce 243,487
HB - Economic Theory and Demography 223,998
HG - Finance 201,619
HN - Social History and Conditions 123,709
HE - Transportation and Communications 111,209
HT - Communities, Classes, Races 108,457
HM - Sociology 106,535
HX - Socialism, Communism, Anarchism 83,315
HJ - Public Finance 79,976
HA - Statistics 57,064
H - Social Science 42,085
HS - Societies 15,390
F - General American History 3
B - Philosophy 2
E - United States History 2
N - Visual Arts 2
NC - Drawing, Design, Illustration 1
PS - American Literature 1