Columbia subject headings:
Circus owners--United States--Biography.
Circus--United States.
Ringling Brothers Barnum and Bailey Combined Shows--History.
Ringling Brothers--History.
Harvard subject headings:
Circus performers--United States--Biography.
Circus--United States.
Ringling Brothers Barnum and Bailey Combined Shows--History.
Ringling Brothers--History.
Princeton subject headings:
Circus owners--United States--Biography.
Circus--United States.
Ringling Brothers Barnum and Bailey Combined Shows--History.
Ringling Brothers--History.