Rondels in North Rhine -Westphalia : A closer look on the western periphery of the rondel phenomenon - Scharl, Silviane; Avci, Nina; Calenborn, Lisa; Röpke, Astrid; Suhrbier, Stefan; Wohlfarth, Christine; Zerl, Tanja; Ziesché, Alexandra (Verlag Marie Leidorf GmbH, 2023)