# How to refer to labels in other documents? [duplicate]

I have two documents file1.tex and file2.tex in two different folds fold1 and fold2, which are in the fold father.

In file1, I defined \label{file1:hello}, how do I use it in file2?

• I think the xr package would help. Feb 12 '14 at 20:51
• If you wish to cross-reference with the aid of hyperref, then see Does hyperref work between two files? Feb 12 '14 at 20:53
• @Werner how to set the relative path correct? Feb 12 '14 at 20:58
• @MaMing: You should read the linked post. It requires you to define (say) \externaldocument{../fold2/file2} in file1.tex. Then you would use the label as-is: \label{hello}. Otherwise, if you may have duplicate labels (hello in file1.tex and hello in file2.tex), then you should use \externaldocument[<prefix>]{...}. Feb 12 '14 at 21:01

I replace here the same answer given for this question: in this case solutions are for files in the same folder.

# Solution 1

You can use the xr package to reference to other LaTeX document.

In the file supplementmain.tex you say:

\usepackage{xr}
\externaldocument{supplement}
...
\ref{ext:supplement}


Note: normally xr doesn't add hyperlinks. Use zref package for this. You only need to replace \externaldocument with \zexternaldocument.

# Solution 2

A minimal working example taken from the following site: GUIT

First.tex

\documentclass[a4paper]{book}
\usepackage[T1]{fontenc}
\usepackage[utf8]{inputenc}

\usepackage{xr-hyper}
\usepackage{hyperref}
\externaldocument[S-]{Second}[Second.pdf]
\begin{document}
\chapter{One}\label{chp:one}
\chapter{Two}\label{chp:two}
Bla Bla Bla.
\end{document}


Second.tex

\documentclass[a4paper]{book}
\usepackage[T1]{fontenc}
\usepackage[utf8]{inputenc}

\usepackage{xr-hyper}
\usepackage{hyperref}
\externaldocument[F-]{First}[First.pdf]
\begin{document}
\chapter{Beginning}\label{chp:One}
Hello!
\chapter{Continuation}
I read chapters~\ref{F-chp:one}~and~\ref{F-chp:two} of the first file.

\end{document}


GUIT also says that in this way you have the hyperlink to the first file.

If files are in different folders, you can add paths into \externaldocument