Population : facts and methods of demography 2026-02-15T14:58:43+03:00 DEBUG: VuFind\ILS\Driver\Folio: Token taken from global cache: eyJhbGciOiJIUzI1NiJ9.eyJzdWIiO... - Keyfitz, Nathan, 1913; Flieger, Wilhelm (W. H. Freeman, 1971)