Remove warning

src/tex/allRefs.tex

@@ -27,6 +27,5 @@ mincitenames=2,
   This document is supposed to use \verb \nocite{*} \verb to cite all bibtex entries.
   However, currently some bibtex entries simply do not work. Thus only selected bibtex entries are printed.
 \nocite{*}
-\cite{undefinedReference}
 \printbibliography%[keyword=mathml]
 \end{document}