Shortened footnote and citation:
{{sfn | Ahnert | 2009 | p=}}
* {{cite book | last=Ahnert | first=Frank | title=Einführung in die Geomorphologie | publisher=UTB | publication-place=Stuttgart | date=2009-01-21 | isbn=978-3-8252-8103-8 | language=de}}
Named reference:
<ref name="r107">{{cite book | last=Ahnert | first=Frank | title=Einführung in die Geomorphologie | publisher=UTB | publication-place=Stuttgart | date=2009-01-21 | isbn=978-3-8252-8103-8 | language=de | page=}}</ref>