Add references in Beamer presentation

Question

I want to add references in my beamer slides like this

I try as follows but it doen't compilate

\documentclass{beamer}
 \usepackage[T1]{fontenc}
 %-----
 \usepackage{amsmath,amssymb,amsfonts} %math
 \usepackage{graphicx}
 \usepackage{color}
  \usetheme{Madrid}

  \begin{document}

  \begin{frame}{}

  \beamertemplatearticlebibitems
 \begin{thebibliography}{10}
 \bibitem{V. M$\ddot{u}$ller, and A. Soltysiak}
 \alert{V. M$\ddot{u}$ller, and A. Soltysiak}
  \newblock  {Spectral radius formula for commuting Hilbert space operators}
  \newblock {\em Studia Math.103. (1992), 329-333}.
  \end{thebibliography}

 \beamertemplatearticlebibitems
 \begin{thebibliography}{10}
 \bibitem{M. Ch$\bar{o}$ and W. $\grave{Z}$elazko}
 \alert{M. Ch$\bar{o}$ and W. $\grave{Z}$elazko}
  \newblock  {On geometric spectral radius of commuting $n$-tuples of 
  operators}
 \newblock {\em Hokkaido Math. J., 21(2): 251-258, 1992}.
 \end{thebibliography}
   \end{frame}

 \end{document} 

Answer 1

Two problems:

• Don't use multiple thebibliography environments, but place all your bibitems in the same one

• You should not try to emulate umlauts and other special characters with math symbols. For example ü should be written as \"u (or use babel for a shorter notation) I don't know which letters you tried to write in your second bibitem, so I just replaced them with o and Z, please look them up yourself.

Off-topic, but you don't need \usepackage{graphicx} and \usepackage{color} with beamer.

---

\documentclass{beamer}
\usepackage[T1]{fontenc}
%-----
\usepackage{amsmath,amssymb,amsfonts} %math
%\usepackage{graphicx}
%\usepackage{color}
\usetheme{Madrid}

\begin{document}

\begin{frame}

\begin{thebibliography}{10}
\bibitem{mueller92}
\alert{V. M\"uller, and A. Soltysiak}
\newblock  {Spectral radius formula for commuting Hilbert space operators}
\newblock {\em Studia Math.103. (1992), 329-333}.

\bibitem{cho92}
\alert{M. Cho and W. Zelazko}
\newblock {On geometric spectral radius of commuting $n$-tuples of  operators}
\newblock {\em Hokkaido Math. J., 21(2): 251-258, 1992}.
\end{thebibliography}
\end{frame}

\end{document}