{{sfn | Schumacher | 2006 | p=}}

* {{cite book | last=Schumacher | first=Ernst | title=Mein Brecht | publisher=Henschel | date=2006 | isbn=978-3-89487-534-3 | language=de}}

<ref name="z424">{{cite book | last=Schumacher | first=Ernst | title=Mein Brecht | publisher=Henschel | date=2006 | isbn=978-3-89487-534-3 | language=de | page=}}</ref>