Citation at the bottom for subfigures in beamer frame

Question

I'm trying to include a citation in a beamer frame following the instruction here. However, I couldn't figure out how to place them inside a subfigure environment. Namely, my code:

\begin{frame}
  \frametitle{Reactive-transport systems}
  \begin{figure}
    \centering
    \begin{subfigure}{0.45\textwidth}
      \includegraphics[width=0.45\textwidth]{Chabanon2017.jpg}
      \caption{Here is text \footfullcite{Chabanon2017}}
    \end{subfigure}
    \begin{subfigure}{0.45\textwidth}
      \includegraphics[width=0.45\textwidth]{Steefel2005.jpg}
      \caption{Here is text \footfullcite{Steefel2005}}
    \end{subfigure}
  \end{figure}
\end{frame}

And this is what I'm seeing:

Any suggestions on how to go around it?

EDIT: Add minimal working example:

\documentclass{beamer}

\usepackage{pgf}
\usepackage{xcolor}
\usepackage[utf8]{inputenc}
% Citation                                                                                                                      
\usepackage[backend=bibtex, style=science]{biblatex}

\usepackage{subcaption}
\usepackage{filecontents}

\begin{filecontents}{vorlage.bib}

 @article{test1,
    author  = {Shen Lin and Brian W. Kernighan},
    title   = {An Effective Heuristic Algorithm for the Travelling-Salesman Problem},
    journal = {Operations Research},
    volume  = {21},
    year    = {1973},
    pages   = {498--516},
 }

@BOOK{test,
  title = {The Infamous Test},
  publisher = {Testington Test},
  year = {2007},
  author = {John Doe},
  address = {Testville},
}

@ARTICLE{test2,
  author = {Testi, T.},
  year = {2003},
  title = {Testartikel},
  journal = {Testjournal}
}
\end{filecontents}



% Hacky fix to citation                                                                                                         
\makeatletter
\def\blx@maxline{77}
\makeatother

% Add bibliography file                                                                                                         
\bibliography{vorlage.bib}

\begin{document}

\begin{frame}
\frametitle{Introduction and motivation - the title}
\section[Motivation]{Introduction and motivation}
\begin{figure}
\centering
\begin{subfigure}{.45\textwidth}
  \centering
  \includegraphics[width=\linewidth]{example-image}
  \caption{A subfigure \footfullcite{test}}
  \label{fig:sub1}
\end{subfigure}%
\begin{subfigure}{.45\textwidth}
  \centering
  \includegraphics[width=\linewidth]{example-image}
  \caption{A subfigure \footfullcite{test1}}
  \label{fig:sub2}
\end{subfigure}
\caption{A figure with two subfigures \footfullcite{test2}}
\label{fig:test}
\end{figure}
\end{frame}

\end{document}

This will produce the following result:

and you can see that the citation is stuck underneath each subfigure instead of gathering all at the bottom of the page.

Answer 1

Based on Footfullcitetext and beamer: incremental numbering you could work around the problem like this:

\documentclass{beamer}

%\usepackage{pgf}
%\usepackage{xcolor}
\usepackage[utf8]{inputenc}
% Citation                                                                                                                      
\usepackage[style=science]{biblatex}

\usepackage{subcaption}
\usepackage{filecontents}

\begin{filecontents}{vorlage.bib}

 @article{test1,
    author  = {Shen Lin and Brian W. Kernighan},
    title   = {An Effective Heuristic Algorithm for the Travelling-Salesman Problem},
    journal = {Operations Research},
    volume  = {21},
    year    = {1973},
    pages   = {498--516},
 }

@BOOK{test,
  title = {The Infamous Test},
  publisher = {Testington Test},
  year = {2007},
  author = {John Doe},
  address = {Testville},
}

@ARTICLE{test2,
  author = {Testi, T.},
  year = {2003},
  title = {Testartikel},
  journal = {Testjournal}
}
\end{filecontents}



% Hacky fix to citation                                                                                                         
\makeatletter
\def\blx@maxline{77}
\makeatother

% Add bibliography file                                                                                                         
\bibliography{vorlage.bib}


\DeclareCiteCommand{\footfullcitetext}[\mkbibfootnotetext]
  {\usebibmacro{prenote}}
  {\usedriver
     {\DeclareNameAlias{sortname}{default}}
     {\thefield{entrytype}}}
  {\multicitedelim}
  {\usebibmacro{postnote}}


\begin{document}

\begin{frame}
\frametitle{Introduction and motivation - the title}
\section[Motivation]{Introduction and motivation}
\begin{figure}
\centering
\begin{subfigure}{.45\textwidth}
  \centering
  \includegraphics[width=\linewidth]{example-image}
  \caption{A subfigure\footnotemark[1]}
  \label{fig:sub1}
\end{subfigure}%
\begin{subfigure}{.45\textwidth}
  \centering
  \includegraphics[width=\linewidth]{example-image}
  \caption{A subfigure\footnotemark[2]}
  \label{fig:sub2}
\end{subfigure}
\caption{A figure with two subfigures\footnotemark[3]}
\label{fig:test}
\end{figure}

\addtocounter{footnote}{1}
\footfullcitetext{test}
\addtocounter{footnote}{1}
\footfullcitetext{test1}
\addtocounter{footnote}{1}
\footfullcitetext{test2}
\end{frame}

\end{document}

Answer 2

An alternative to @samcarter's since I done it before see the answer:

\documentclass{beamer}

\usepackage{pgf}
\usepackage{xcolor}
\usepackage[utf8]{inputenc}
% Citation                                                                                                                      
\usepackage[backend=bibtex, style=science]{biblatex}

\usepackage{subcaption}
\usepackage{filecontents}
\newsavebox{\mybox}

\begin{filecontents}{vorlage.bib}

 @article{test1,
    author  = {Shen Lin and Brian W. Kernighan},
    title   = {An Effective Heuristic Algorithm for the Travelling-Salesman Problem},
    journal = {Operations Research},
    volume  = {21},
    year    = {1973},
    pages   = {498--516},
 }

@BOOK{test,
  title = {The Infamous Test},
  publisher = {Testington Test},
  year = {2007},
  author = {John Doe},
  address = {Testville},
}

@ARTICLE{test2,
  author = {Testi, T.},
  year = {2003},
  title = {Testartikel},
  journal = {Testjournal}
}
\end{filecontents}



% Hacky fix to citation                                                                                                         
\makeatletter
\def\blx@maxline{77}
\makeatother

% Add bibliography file                                                                                                         
\bibliography{vorlage.bib}

\begin{document}

\begin{frame}
\frametitle{Introduction and motivation - the title}
\section[Motivation]{Introduction and motivation}
\begin{figure}
\centering
\begin{subfigure}{.45\textwidth}
  \centering
  \includegraphics[width=\linewidth]{example-image}
  \caption{A subfigure\footnotemark[1]}% \footfullcite{test}}
  \label{fig:sub1}
\end{subfigure}%
\begin{subfigure}{.45\textwidth}
  \centering
  \includegraphics[width=\linewidth]{example-image}
  \caption{A subfigure \footnotemark[2]}
  \label{fig:sub2}
\end{subfigure}
\caption{A figure with two subfigures\footnotemark[3]}% \footfullcite{test2}}
\label{fig:test}
\end{figure}
\sbox1{\hbox{\footfullcite[1]{test}
\footfullcite[2]{test1}
\footfullcite[3]{test2}}}
\end{frame}

\end{document}

PS: The output is the same but I just used the \footnotemark[] trick and let the \footfullcite commands to be expanded inside an \sbox (but actually outside of it). The good part is that no need of advanced bib(La)TeX knowledge is needed...