Al-Malabeh, A., & Kempe, S. (2016). Origin of Iron Ore Nuggets (“Bohnerze”) through Weathering of Basalt as Documented by Pebbles from the Herbstlabyrinth, Breitscheid-Germany. Acta Carsologica, 34(2). https://doi.org/10.3986/ac.v34i2.271