Columbia subject headings:
Harvard subject headings:
Ilhavo (Portugal)--Emigration and immigration.
Ilhavo (Portugal)--Population--Statistics.
Murtosa (Portugal)--Emigration and immigration.
Murtosa (Portugal)--Population--Statistics.
Princeton subject headings:
Ilhavo (Portugal)--Social conditions.
Murtosa (Portugal)--Social conditions.
Portugal--Emigration and immigration.