Portuguese migration studies.
D003247:Conservation of Natural Resources; D003710:Demography; D019049:Developed Countries; D004467:Economics; D004641:Emigration and Immigration; D004736:Energy-Generating Resources; D004777:Environment; D005060:Europe; D011057:Politics; D011153:Population; D011157:Population Dynamics; D011174:Portugal; D012959:Socioeconomic Factors
Demographic Factors; Developed Countries; Economic Factors; Energy Supply; Environment; Europe; International Migration; Literature Review; Migration; Natural Resources; Political Factors; Population; Population Dynamics; Portugal; Socioeconomic Factors; Southern Europe