[Roman Michałowski: The Gniezno Summit. The Religious Premises of the Founding of the Archbishopric of Gniezno] - Krafft, Otfried (. Zeitschrift für Ostmitteleuropa-Forschung. - Marburg, L. : Verl. Herder-Inst., 1952-. - Online-Ressource. - ISSN 2701-0449 67, 2018)