https://shkola.obozrevatel.com/ukr/gdz/7klass/istorija_ukrainy/meloch-2020/razdel-2-rus-ukraina-kontse-x-pervoj-polovine-xi-v/11-politicheskoe-ustrojstvo-obschestvennoe-i-hozyajstvennuyu-zhizn-rusi-ukrainyi-v-epohu-rastsveta/