Columbia subject headings:
Emigration and immigration--Congresses.
Migration, Internal, in literature--Congresses.
Migration, Internal--Social aspects--Africa--Congresses.
Harvard subject headings:
Migration, Internal, in literature--Congresses.
Migration, Internal--Social aspects--Africa--Congresses.
Princeton subject headings:
Migration, Internal, in literature--Congresses.
Migration, Internal--Social aspects--Africa--Congresses.