Columbia subject headings:
Harvard subject headings:
Immigrants--Ghana--Northern Region--Economic conditions.
Nigeria--Emigration and immigration--History--20th century.
Northern Region (Ghana)--Commerce--History--20th century.
Northern Region (Ghana)--Economic conditions.
Northern Region (Ghana)--Emigration and immigration--Economic aspects--History--20th century.
Northern Region (Ghana)--History--20th century--Emigration and immigration--Economic aspects.
Yoruba (African people)--Commerce--Ghana--Northern Region--History--20th century.
Princeton subject headings:
Immigrants--Ghana--Northern Region--Economic conditions.
Nigeria--Emigration and immigration--History--20th century.
Northern Region (Ghana)--Commerce--History--20th century.
Northern Region (Ghana)--Economic conditions.
Northern Region (Ghana)--Emigration and immigration--Economic aspects--History--20th century.
Yoruba (African people)--Commerce--Ghana--Northern Region--History--20th century.