{{sfn | Berg | 1999 | p=}}

* {{cite book | last=Berg | first=Hubert van den | title=Avantgarde und Anarchismus | publisher=C. Winter | publication-place=Heidelberg | date=1999 | isbn=3-8253-0852-9 | language=de}}

<ref name="k870">{{cite book | last=Berg | first=Hubert van den | title=Avantgarde und Anarchismus | publisher=C. Winter | publication-place=Heidelberg | date=1999 | isbn=3-8253-0852-9 | language=de | page=}}</ref>