Wilke, Gerard. “Pole Arm from Underwater Excavation on the Relics of a Bridge at the Slavic Defensive Settlement at Olsborg in Plön, on the Großer Plöner See Lake, Northern Germany”. Acta Universitatis Lodziensis. Folia Archaeologica, no. 36, Dec. 2021, pp. 395-20, doi:10.18778/0208-6034.36.19.