Journal Article Demographic Factors 12 Developed Countries 12 Europe 12 Population 12 Population Dynamics 12 Portugal 11 Southern Europe 11 English Abstract 10 Migration 7 International Migration 6 Economic Factors 5 Historical Survey 5 Historical Article 4 Demography 3 Migration Policy 3 Policy 3 Population Characteristics 3 Population Policy 3 Social Policy 3 Social Sciences 3 Socioeconomic Factors 3 Comparative Studies 2 Comparative Study 2 Developing Countries 2 Fertility 2 Migrants 2 Social Change 2 Socioeconomic Status 2 Americas 1