Citation not found if bib file in parent directory

Question

My citations work fine when the sources.bib file is within the same directory as my .tex file, as shown here:

\documentclass{article}
\usepackage{fancyhdr}

\begin{document}

\thispagestyle{fancy}
\everymath{\displaystyle}

\nocite{textbook}

\bibliographystyle{plain}
\bibliography{sources}

\end{document}

Here is the sources.bib file:

@book{textbook,
    author = {First, Last},
    title = {title},
}

My bibliography shows up just fine. However, if I simply move sources.bib outside into the parent directory, and adjust the code:

\documentclass{article}
\usepackage{fancyhdr}

\begin{document}

\thispagestyle{fancy}
\everymath{\displaystyle}

\nocite{textbook}

\bibliographystyle{plain}
\bibliography{../sources}

\end{document}

I receive the errors:

Citation `textbook' undefined
Empty `thebibliography' environment
There were undefined references.

What's wrong here?

Answer 1

I've tried the code posted in U.Martinez-Corral's answer, unfortunately it's not work for me (Windows10 + sublime Text 3 (Build 3126) + LaTeXTools + Texlive).

This is a limitation of BibTeX:

Relative paths requiring upward directory traversal (..) don't work when using BibTeX and an output directory. This is a limitation of BibTeX, which doesn't really support the concept of an output directory. Citation not found if bib file in parent directory

Solution 1

Use absolute path instead.

\bibliography{../sources}                         % relative path: don't work
\bibliography{E:/GitKraken/test/sources}          % absolute path: work

Solution 2

My solution is using currfile-abspath package to build an absolute path \bibliography{\mainabsdir/../sources}.

./main.tex

\documentclass[a4paper]{article}
% \usepackage[backend=bibtex]{biblatex}

\usepackage{currfile-abspath}

\getmainfile % get real main file (can be different than jobname in some cases)
\getabspath{\themainfile} % or use \jobname.tex instead (not as safe)
\let\mainabsdir\theabsdir % save result away (macro will be overwritten by the next \getabspath
\let\mainabspath\theabspath % save result away (macro will be overwritten by the next \getabspath

\begin{document}

\cite{knuth1986texbook}

\bibliographystyle{plain}
\bibliography{\mainabsdir/../sources}

\end{document}

See Also: https://tex.stackexchange.com/a/54891/115852

Answer 2

Although it should have no effect in this case, it's better to keep the Minimum Working Example (MWE) the smallest possible, and provide all the files required to test it. The MWE is lacking the fancy style definition. Removing it and \everymath, and adding the content of the bibfile, this MWE works for me:

./main.tex

\documentclass[a4paper]{article}
\begin{document}

\cite{knuth1986texbook}

\bibliographystyle{plain}
\bibliography{../sources}

\end{document}

../sources.bib

@book{knuth1986texbook,
  keywords = {book},
  title={The texbook},
  author={Knuth, D.E. and Bibby, D.},
  volume={1993},
  year={1986},
  publisher={Addison-Wesley}
}

Just to be sure, remove all the auxiliary files and compile the whole sequence again (pdflatex + bibtex + pdflatex + pdflatex). Is it still not working?