* {{cite book | last=Grote | first=Georg | last2=Obermair | first2=Hannes | title=A Land on the Threshold | publisher=Peter Lang Gmbh, Internationaler Verlag Der Wissenschaften | publication-place=Oxford Bern Berlin Bruxelles Frankfurt am Main New York Wien | date=2017 | isbn=978-3-0343-2240-9 | language=de}}
<ref name="e176">{{cite book | last=Grote | first=Georg | last2=Obermair | first2=Hannes | title=A Land on the Threshold | publisher=Peter Lang Gmbh, Internationaler Verlag Der Wissenschaften | publication-place=Oxford Bern Berlin Bruxelles Frankfurt am Main New York Wien | date=2017 | isbn=978-3-0343-2240-9 | language=de | page=}}</ref>