Columbia subject headings:
Earth (Planet)--Crust--Congresses.
Plate tectonics--History--Congresses.
Harvard subject headings:
Earth (Planet)--Crust--Congresses.
Earth (Planet)--Crust.
Plate tectonics--History--Congresses.
Plate tectonics--History.
Princeton subject headings:
Earth (Planet)--Crust.
Plate tectonics--History.