Shortened footnote and citation:
{{sfn|Pörksen|1980|p=}}
* {{cite book | last=Pörksen | first=Erich | title=Die Wahrzeichen der Insel Amrum | publisher=Breklumer Verlag | publication-place=Breklum | date=1980 | isbn=3-7793-1119-4 | language=de}}
Named reference:
<ref name="e542">{{cite book | last=Pörksen | first=Erich | title=Die Wahrzeichen der Insel Amrum | publisher=Breklumer Verlag | publication-place=Breklum | date=1980 | isbn=3-7793-1119-4 | language=de | page=}}</ref>