Columbia subject headings:
Harvard subject headings:
Bracken fern--Congresses.
Bracken fern.
Pteridophyta--Congresses.
Pteridophyta.
Princeton subject headings:
Pteridium--Control--Great Britain--Congresses.
Pteridium--Ecology--Congresses.
Weeds--Control--Great Britain--Congresses.
Weeds--Great Britain--Congresses.