Frouz, J., Tajovský, K., Rusek, J., Heinkele, T. (1999): Development of Ah horizons in colliery spoil heaps in the Sokolov mining district (Czech Republic) and in dump soils of the Lusatian mining district (Germany). International Symposium Ecology of post-mining landscapes EcoPoL´99. Abstracts. Brandenburg University of Technology at Cottbus, Germany, March 15-19, 1999: 1 p.