Columbia subject headings:
Earthquakes--Chile--Valdivia--History--20th century.
Harvard subject headings:
Earthquakes--Chile--Valdivia--History--20th century.
Princeton subject headings:
Earthquakes--Chile--Valdivia--History--20th century.
Flood control--Chile--Riñihue, Lake--History--20th century.
Floods--Chile--Valdivia--History--20th century.
Valdivia (Chile)--History--20th century.