Shortened footnote and citation:
{{sfn | Haerkötter | Haerkötter | 1989 | p=}}
* {{cite book | last=Haerkötter | first=Gerd | last2=Haerkötter | first2=Marlene | title=Macht und Magie der Bäume | publisher=Eichborn | publication-place=Frankfurt am Main | date=1989 | isbn=3-8218-1226-5 | language=de}}
Named reference:
<ref name="y115">{{cite book | last=Haerkötter | first=Gerd | last2=Haerkötter | first2=Marlene | title=Macht und Magie der Bäume | publisher=Eichborn | publication-place=Frankfurt am Main | date=1989 | isbn=3-8218-1226-5 | language=de | page=}}</ref>