Columbia subject headings:
Uruguay--Boundaries.
Harvard subject headings:
Argentina--Foreign relations--Uruguay.
Brazil--Foreign relations--Uruguay.
Río de la Plata (Argentina and Uruguay)
Uruguay River.
Uruguay--Boundaries.
Uruguay--Foreign relations--Argentina.
Uruguay--Foreign relations--Brazil.
Princeton subject headings:
Argentina--Foreign relations--Uruguay.
Brazil--Foreign relations--Uruguay.
Río de la Plata (Argentina and Uruguay)
Uruguay River.
Uruguay--Boundaries.
Uruguay--Foreign relations--Argentina.
Uruguay--Foreign relations--Brazil.