H.W. Oosterink, Th. Simon, H. Hagdorn and H. Winkelhorst 2006. Geo (Im) pulse A subrosion pipe fill in the Lower Muschelkalk, Winterswijk Quarry, Eastern Netherlands. Netherlands Journal of Geosciences. 85, (Dec. 2006), 293 - 297. DOI:https://doi.org/10.1017/S0016774600023088.