1. Characteristics of seismic activity of the Upper Silesian Coal Basin in Poland
2. Popiołek E., Ostrowski J., Czaja J., Mazur J., 10th FIG International Symposium on Deformation Measurements, 77 (Orange, California, USA, 2001)
3. Krawczyk A. Perski Z., 11th International Congress of the International Society for Mine Surveying 2, 209 (Cracow, Poland, 2000)
4. Popiołek E., Marcak H., Krawczyk A., Warsztaty 2006: Natural hazards in mining, 339 (2006)