Columbia subject headings:
Basic needs--Peru--Congresses.
Peru--Population--Congresses.
Peru--Social conditions--1968---Congresses.
Harvard subject headings:
Basic needs--Peru--Congresses.
Peru--Population--Congresses.
Peru--Social conditions--1968---Congresses.
Princeton subject headings:
Basic needs--Peru--Congresses.
Peru--Population--Congresses.
Peru--Social conditions--1968---Congresses.