Columbia subject headings:
Coal miners--Health and hygiene--United States.
Coal miners--Labor unions.
Lungs--Dust diseases--Social aspects.
Harvard subject headings:
Coal miners--Diseases and hygiene--United States.
Coal miners--Labor unions
Lungs--Dust diseases--Social aspects.
Princeton subject headings:
Coal miners--Diseases and hygiene--United States.
Coal miners--Labor unions.
Lungs--Dust diseases--Social aspects.