Shortened footnote and citation:
{{sfn | Gebhardt | 1998 | p=}}

* {{cite book | last=Gebhardt | first=Selma | title=Von der Kaurimuschel zur Kreditkarte | publisher=Rosenholz-Verl | publication-place=Kiel | date=1998 | isbn=3-931665-10-0 | language=de}}


Named reference:
<ref name="z631">{{cite book | last=Gebhardt | first=Selma | title=Von der Kaurimuschel zur Kreditkarte | publisher=Rosenholz-Verl | publication-place=Kiel | date=1998 | isbn=3-931665-10-0 | language=de | page=}}</ref>