K probleme social'nogo razvitija rannesrednevekovoj Vostočnoj i Central'noj Evropy: sravnitel'nyj analiz archeologičeskich dannych. Concerning the social development of the eastern and central Europe: comparative analysis of the archaeological data - Rier, Ja. G. (Rossijskaja Archeologija, 1996,1 (1996), 1996)