Köhler and Clausing, 2000
From dinoflaj3
Köhler, J. and Clausing, A., 2000: Taxonomy and palaeoecology of dinoflagellate cysts from Upper Oligocene freshwater sediments of Lake Enspel, Westerwald area, Germany. Review of Palaeobotany and Palynology, v.112, p.39-49, pl.1.