1st contribution by Timon Demburg

Supervisors: Prof.in F. Heinzel & Prof.in E. Rathgeb-Schnierer

________________________________

2nd contribution by Elisa Wagner

Supervisors: Prof. T. Fritzlar & Prof. R.-T. Kramer

________________________________

3rd contribution by Damaris Hottenroth

Supervisors: Prof.in E. Rathgeb-Schnierer & Prof.in M. Domenech