Columbia subject headings:
Labor unions--Officials and employees--United States--Biography.
Lewis, John L. (John Llewellyn), 1880-1969.
United Mine Workers of America--History.
Harvard subject headings:
Labor leaders--United States--Biography
Labor unions--United States--Officials and employees--Biography
Lewis, John L. (John Llewellyn), 1880-1969.
United Mine Workers of America--History.
Princeton subject headings:
Labor unions--United States--Officials and employees--Biography.
Lewis, John L. (John Llewellyn), 1880-1969.
United Mine Workers of America--History.