Columbia subject headings:
Europe--Politics and government--1989-
Organization for Security and Co-operation in Europe.
Security, International.
Summit meetings--Portugal--Lisbon.
Harvard subject headings:
Europe--Politics and government--1989-
Organization for Security and Co-operation in Europe.
Security, International
Summit meetings--Portugal--Lisbon.
Princeton subject headings:
Europe--Politics and government--1989-
Organization for Security and Co-operation in Europe.
Security, International.
Summit meetings--Portugal--Lisbon.