Columbia subject headings:
Convict labor--United States.
Occupational training--United States.
Prison industries--United States.
Prisoners--Training of--United States.
Harvard subject headings:
Convict labor--United States.
Occupational training--United States
Prison industries--United States.
Prisoners--Training of--United States.
Princeton subject headings:
Convict labor--United States.
Occupational training--United States.
Prison industries--United States.
Prisoners--Training of--United States.