1
by Altmeppen, Klaus-Dieter
Published 2017
Nomos Verlagsgesellschaft mbH & Co. KG

2
by Rittmann, Günter
Published 2014
Nomos Verlagsgesellschaft mbH & Co. KG

3
by Reimer, Torsten
Published 2019
MDPI - Multidisciplinary Digital Publishing Institute