Include a tex file that contains the bibliography section

I found when I tried to keep the spaces in my file name by using \include{{""}}, then the file could still be included, but the references would be question marks.

This is my MWE

\documentclass{article}

\usepackage[sort, authoryear, round]{natbib}
\bibliographystyle{unsrtnat}

\begin{document}

\include{{"Sections/The study plan"}}

\bibliography{References.bib}
\end{document}


The file /Sections/The study plan.tex

\section{The study plan}
\citep{abc}


The file /References.bib

 @Article{abc,
Author                   = {Adams, D. W. and Errington, J. },
Journal                  = {Nat. Rev },
Year                     = {2003},

Month                    = {Sep},
Number                   = {9},
Pages                    = {64--65},
Volume                   = {7}
}


If I delete the spaces in my file name, and use \include{}, it works fine. For example, if I rename \Sections\The study plan.tex as \Sections\Thestudyplan.tex and use \include{Sections/Thestudyplan}, the reference will show up fine.

I know you might say "just delete the spaces", or "use input instead" etc etc, but I wonder if there is way to keep the spaces in the file names and still use include. Thanks!

• I'd say you can try \include{"Sections/The study plan"} (no double braces), but my advice is, as you predicted, don't use space in file names. – egreg Jan 10 '16 at 23:04
• Of course I tried \include{"Sections/The study plan"}. This way the include wouldn't work at all, not just the natbib. – fyang Jan 11 '16 at 0:07
• What might be the reason for preferring \include over \input? Incidentally, it should be \bibliography{References}, not \bibliography{References.bib}, i.e, you should omit the .bib extension. – Mico Jan 11 '16 at 1:03
• I've taken the liberty of editing the title of your posting, as the issue you're encountering isn't linked directly to the natbib package. – Mico Jan 11 '16 at 1:17
• @Mico, no. \include starts a new page, \input doesn't. \includes can be managed with includeonly (unsure about exact syntax, sorry), no control over \input available. – vonbrand Jan 11 '16 at 1:37

I can see no compelling reason for using \include in the setup you describe. The \input instruction seems to be tailor-made for just the case at hand.
\documentclass{article}