Columbia subject headings:
Actinide elements--Congresses.
Actinium compounds--Congresses.
Plutonium compounds--Congresses.
Plutonium--Congresses.
Harvard subject headings:
Princeton subject headings:
Actinide elements--Congresses.
Actinium compounds--Congresses.
Plutonium compounds--Congresses.
Plutonium--Congresses.