Columbia subject headings:
Migration, Internal--Senegal River Valley.
Peasants--Senegal River Valley--Economic conditions.
Senegal River Valley--Economic conditions.
Harvard subject headings:
Migration, Internal--Senegal River Valley.
Peasants--Senegal River Valley--Economic conditions.
Senegal River Valley--Economic conditions.
Princeton subject headings:
Senegal River Valley--Emigration and immigration--Economic aspects.
Senegal River Valley--History.