Reference

I. Lakova, Elena-Koleva Rekalova, Daria Ivanova, Lyubomir Metodiev, Silviya Petrova (2008): Transgressive-regressive Cycles in the Tithonian and Berriasian Pelagic Limestones of the West Balkan Unit, Bulgaria – Berichte der Geologischen Bundesanstalt – 74: 47 - 48.