1
by René Hefti
Published 2018
MDPI AG - Multidisciplinary Digital Publishing Institute

2
by Dopheide, Christian
Published 2017
Nomos Verlagsgesellschaft mbH & Co. KG

3
by Altmeppen, Klaus-Dieter
Published 2017
Nomos Verlagsgesellschaft mbH & Co. KG

4
by Wineburg, Robert
Published 2019
MDPI - Multidisciplinary Digital Publishing Institute