Experimental design for applying geophysical methods in investigating the spatial distribution of hard formations in the excavation face of bucket wheel excavators Journal title: Górnictwo Odkrywkowe Authors: Miltiades Triantafyllou, S. Pirtses, L. Myronidis, Christos Roumpos, Fragkiskos Pavloudakis, Theodor... Subject(s): Mineralogy, Mining, Science