Separate bibliographies with different label prefixes for sections, all citing from mixed bib files

Question

I'm working on an article: main text (M) + appendix (X), both citing from two .bib files A.bib, B.bib, using biblatex.

I want to produce two separate bibliographies for M and X with different label prefixes for each (e.g. M1, M2, M3; and X1, X2, X3).

With refsection I was able to get separate bibliographies, but not different label prefixes.

\documentclass{article}

\usepackage{filecontents}
\usepackage{biblatex}

\begin{filecontents}{A.bib}
    @Book{Knuth:1990,
        author    = {Knuth, Donald E.},
        title     = {The {\TeX}book},
        year      = {1990},
        isbn      = {0-201-13447-0},
        publisher = {Addison\,\textendash\,Wesley},
    }   
\end{filecontents}
\begin{filecontents}{B.bib}
    @Book{Lamport:94,
        author    = {Lamport, Leslie},
        title     = {\LaTeX: A Document Preparation System},
        year      = {1994},
        isbn      = {0-021-52983-1},
        publisher = {Addison\,\textendash\,Wesley},
    }
\end{filecontents}

\addbibresource{A.bib}
\addbibresource{B.bib}

\begin{document}

    \section{Section One}
    Text \parencite{Lamport:94}.

    \section{Section Two}
    Text \parencite{Knuth:1990}.

    \printbibliography

    \appendix

    \section{Appendix One}
    \begin{refsection}
        Text \parencite{Knuth:1990}
        Text \parencite{Lamport:94}

        \printbibliography
    \end{refsection}

\end{document}

Any (simple) way to do that?

Answer 1

You can use the labelprefix option to \newrefcontext.

Just add \newrefcontext[labelprefix=M] for the main part and \newrefcontext[labelprefix=X] for the appendix.

\begin{document}
\newrefcontext[labelprefix=M]
\section{Section One}
Text \parencite{Lamport:94}.

\section{Section Two}
Text \parencite{Knuth:1990}.

\printbibliography

\appendix
\section{Appendix One}
\begin{refsection}
\newrefcontext[labelprefix=X]
  Text \parencite{Knuth:1990}
  Text \parencite{Lamport:94}

  \printbibliography
\end{refsection}
\end{document}