How to add footnote citation to Beamer slides

A citation that appears as a footnote can be added to Beamer slides by using the biblatex package and its footcite command.

For example:

%...

\usepackage{biblatex}
\bibliography{children-songs}

%...

\begin{frame}{Humpty and Dumpty}
This is about his fall \footcite{Humpty1912}
\end{frame}