I.  Zagorchev, ?Pre-Paleogene alpine tectonics in southwestern Bulgaria?, Geologica Balcanica, vol. 25, pp. 91?112, 1995.

I.  Zagorchev, ?Introduction to the geology of SW Bulgaria?, Geologica Balcanica, vol. 31, pp. 3?52, 2001.

C.  Dabowski, Boyanov, I., Khrischev, K. H., Nikolov, T., Sapunov, I., Yanev, Y., and Zagorchev, I., ?Structure and alpine evolution of Bulgaria?, Geologica Balcanica, vol. 32, pp. 9?12, 2002.