Columbia subject headings:
Labor--Social aspects--Portugal--Case studies.
Portugal--Emigration and immigration--Case studies.
Return migration--Portugal--Case studies.
Harvard subject headings:
Labor--Social aspects--Portugal--Case studies.
Portugal--Emigration and immigration--Case studies.
Return migration--Portugal--Case studies.
Working class--Social aspects--Portugal--Case studies.
Princeton subject headings:
Portugal--Emigration and immigration.
Return migration--Portugal.