Automatically split sources list into bibliography and references

Question

I am currently reading up on how to properly format used resources. Doing so I found out it is customary to distinguish between references and bibliography, the former being the list of sources actually referenced in the text, like

This was finding was made by Smith (2008)

and the latter being a list of materials used by the author that are not directly referenced in the text.

I would like to achieve this format with biblatex. Consider the following example

main.tex:

\documentclass{article}

\usepackage[american]{babel}
\usepackage[backend=biber, bibencoding=utf8, style=apa, natbib=true]{biblatex}

\DeclareLanguageMapping{american}{american-apa}

\addbibresource{sample.bib}

\begin{document}

A discussion of the subject can be found in \citet{Smith08}.
\nocite{Baker10}

\printbibliography[]

\end{document}

sample.bib:

@book{Smith08,
    author = {Smith, E.},
    year = {2008},
    title = {The other book},
}

@book{Baker10,
    author = {Baker, M.},
    year = {2010},
    title = {The book},
}

I would like the sources list generated to look like this, as Baker (2010) was not directly referenced but Smith (2008) was:

Bibliography

Baker, M. (2010). The book.

References

Smith, E. (2008). The other book.

I suspect this can be done with \DeclareBibliographyCategory somehow, but I can't figure out how.

But maybe there is even a better way as this seems like a standard format.

Answer 1

You can split your bibliography and then append keywords to identify different bibliography entries. A MWE:

    \documentclass{article}

    \usepackage[american]{babel}
    \usepackage[backend=biber, bibencoding=utf8, style=apa, natbib=true]{biblatex}

    \DeclareLanguageMapping{american}{american-apa}


    \usepackage{filecontents}

    \begin{filecontents}{biblatextest1.bib}
    @book{Baker10,
        author = {Baker, M.},
        year = {2010},
        title = {The book},
    }
    \end{filecontents}
    %
    \begin{filecontents}{biblatextest2.bib}
    @book{Smith08,
        author = {Smith, E.},
        year = {2008},
        title = {The other book},
    }
    \end{filecontents}

    \addbibresource{biblatextest1.bib}
    \addbibresource{biblatextest2.bib}

    %Append keywords to identify different bibliography entries.
    \DeclareSourcemap{
        \maps[datatype=bibtex, overwrite]{
            \map{
                \perdatasource{biblatextest1.bib}
                \step[fieldset=KEYWORDS, fieldvalue=primary, append]
            }
            \map{
                \perdatasource{biblatextest2.bib}
                \step[fieldset=KEYWORDS, fieldvalue=secondary, append]
            }
        }
    }
    \begin{document}

    A discussion of the subject can be found in \cite{Smith08}.
    \nocite{Baker10}

    \printbibliography[title=Bibliography, keyword=primary]
    \printbibliography[title=References, keyword=secondary]

    \end{document}

With only a bib source declaring a category:

\documentclass{article}

\usepackage[american]{babel}
\usepackage[backend=biber, bibencoding=utf8, style=apa, natbib=true]{biblatex}

\DeclareLanguageMapping{american}{american-apa}



\usepackage{filecontents}

\begin{filecontents}{biblatextest.bib}
@book{Baker10,
    author = {Baker, M.},
    year = {2010},
    title = {The book},
}
@book{Smith08,
    author = {Smith, E.},
    year = {2008},
    title = {The other book},
}
\end{filecontents}

\addbibresource{biblatextest.bib}

\DeclareBibliographyCategory{cited}
\AtEveryCitekey{\addtocategory{cited}{\thefield{entrykey}}}


\begin{document}

A discussion of the subject can be found in \cite{Smith08}.
\nocite{Baker10}

\printbibliography[title=Bibliography,notcategory=cited]
\printbibliography[title=References,category=cited]

\end{document}