http://general-terms.thesaurus.ekt.gr/vocabhttp://general-terms.thesaurus.ekt.gr/vocab?tema=9801internal migration http://general-terms.thesaurus.ekt.gr/vocab?tema=9801 urban- rural migration NT http://general-terms.thesaurus.ekt.gr/vocab?tema=9801 rural-urban migration NT http://general-terms.thesaurus.ekt.gr/vocab?tema=9801 geographic mobility BT