Columbia subject headings:
Central America--Politics and government.
Peace treaties--Central America.
Harvard subject headings:
Arias Sánchez, Oscar--Travel--Washington (D. C.)
Central America--Foreign relations--United States.
Central America--Politics and government.
Costa Rica--Foreign relations--1986-
Negotiation--History.
Peace treaties.
United States--Foreign relations--Central America.
Princeton subject headings:
Arias Sánchez, Óscar.
Central America--Foreign relations--1979-
Central America--Foreign relations--United States.
Costa Rica--Politics and government--1948-1986.
Costa Rica--Politics and government--1986-
Counterrevolutionaries--Nicaragua.
Iran-Contra Affair, 1985-1990.
Peace.
United States--Foreign relations--Central America.