Columbia subject headings:
Argentina--Foreign relations--Bolivia.
Argentina--Foreign relations--Paraguay.
Bolivia--Foreign relations--Argentina.
Chaco Boreal (Paraguay and Bolivia)
Paraguay--Foreign relations--Argentina.
Harvard subject headings:
Argentina--Foreign relations--Bolivia.
Argentina--Foreign relations--Paraguay.
Bolivia--Foreign relations--Argentina.
Chaco Boreal (Paraguay and Bolivia)
Paraguay--Foreign relations--Argentina.
Princeton subject headings: