Columbia subject headings:
Rural population--France--Artois--History.
Rural population--France--Boulonnais--History.
Harvard subject headings:
Artois (France)--Population, Rural--History.
Boulonnais (France)--Population, Rural--History.
Princeton subject headings:
Artois (France)--Population, Rural--History.
Boulonnais (France)--Population, Rural--History.