Shortened footnote and citation:
{{sfn | Magnus | Popp | Sextro | 2008 | p=}}
* {{cite book | last=Magnus | first=Kurt | last2=Popp | first2=Karl | last3=Sextro | first3=Walter | title=Schwingungen | publisher=Springer Science & Business Media | publication-place=Wiesbaden | date=2008-04-11 | isbn=978-3-8351-0193-7 | language=de}}
Named reference:
<ref name="x212">{{cite book | last=Magnus | first=Kurt | last2=Popp | first2=Karl | last3=Sextro | first3=Walter | title=Schwingungen | publisher=Springer Science & Business Media | publication-place=Wiesbaden | date=2008-04-11 | isbn=978-3-8351-0193-7 | language=de | page=}}</ref>