Population patterns in the past 2026-02-15T13:12:32+03:00 DEBUG: VuFind\ILS\Driver\Folio: Token taken from global cache: eyJhbGciOiJIUzI1NiJ9.eyJzdWIiO... - Easterlin, Richard A.; Lee, Ronald Demos, 1941-; Lindert, Peter H.; Walle, Etienne van de (Studies in social discontinuity, 1977)