The system of main cities:  a critique and an empirical evaluation.
D003710:Demography; D019049:Developed Countries; D004641:Emigration and Immigration; D005060:Europe; D005061:Europe, Eastern; D005069:Evaluation Studies as Topic; D005843:Geography; D011044:Poland; D011153:Population; D011154:Population Characteristics; D011157:Population Dynamics; D012942:Social Sciences; D014505:Urban Population; D014507:Urbanization
Critique; Demographic Factors; Developed Countries; Eastern Europe; Europe; Geographic Factors; Geography; Human Geography; Migration; Migration, Internal; Poland; Population; Population Characteristics; Population Dynamics; Social Sciences; Spatial Distribution; Urban Population; Urban Spatial Distribution; Urbanization