Shortened footnote and citation:
{{sfn|Maturana|Varela|2009|p=}}
* {{cite book | last=Maturana | first=Humberto R. | last2=Varela | first2=Francisco J. | title=Der Baum der Erkenntnis | publisher=FISCHER Taschenbuch | publication-place=Frankfurt am Main | date=2009 | isbn=978-3-596-17855-1 | language=de}}
Named reference:
<ref name="f443">{{cite book | last=Maturana | first=Humberto R. | last2=Varela | first2=Francisco J. | title=Der Baum der Erkenntnis | publisher=FISCHER Taschenbuch | publication-place=Frankfurt am Main | date=2009 | isbn=978-3-596-17855-1 | language=de | page=}}</ref>