Reference
Fritz F. Steininger, Gudrun Daxner-Höck [Daxner], Margit Haas, Johanna Kovar-Eder, Hermann J. Mauritsch, Barbara Meller, R.M. Scholger (1997): Stratigraphy of the "Basin Fill" in the Early Miocene Lignite Opencast Mine Oberdorf (N Voitsberg, Styria, Austria) – Jahrbuch der Geologischen Bundesanstalt – 140: 491 - 496.