Shotyk, W. [P:(DE-HGF)0] ; Krachler, M. [P:(DE-Juel1)VDB824] ; Martinez-Cortizas, A. [P:(DE-HGF)0] ; Cheburkin, H. M. [P:(DE-HGF)0] ; Emons, H. [P:(DE-Juel1)VDB350]