title: Spatial barriers:  concepts, use and an application to intra-regional migration.
authors.forename: Z
authors.initials: Z
authors.lastname: Rykiel
mesh_terms: D003710:Demography; D019049:Developed Countries; D004641:Emigration and Immigration; D005060:Europe; D005061:Europe, Eastern; D005843:Geography; D011044:Poland; D011153:Population; D011157:Population Dynamics; D012106:Research
keywords: Demographic Factors; Developed Countries; Eastern Europe; Europe; Geographic Factors; Migration; Migration, Internal; Poland; Population; Population Dynamics; Research Methodology; Spatial Distribution