Reference

Andrei F. Grachev, Oleg A. Korchagin, Vladimir A. Tselmovich, Heinz Albert Kollmann (2009): Morphology and composition of the cosmic dust and micrometeorites in the Transitional Clay Layer at the Cretaceous-Pleogene Boundary in the Gams Section (Eastern Alps) – Berichte der Geologischen Bundesanstalt – 78: 15.