Frydrych, Małgorzata. “Classification of Esker Morphology on Soft Beds in the Area of the Saalian and Elsterian Glaciations in Poland”. Acta Geographica Lodziensia 112 (December 20, 2022): 45–60. Accessed July 3, 2024. https://czasopisma.ltn.lodz.pl/Acta-Geographica-Lodziensia/article/view/1840.