# Is there any way to get references to automatically update between files on one computer

I suspect the title doesn't really do justice to my question, so let me try to explain a bit more carefully. I have a couple of situations now where I'm working simultaneously on closely linked papers that refer to each other a lot. So, Paper 2 will have many citations like [Paper 1, Proposition 4.7].

Now, within one file, LaTeX deals brilliantly with referring to other parts of the same document in a way that is dynamic; if I move things so that Proposition 4.7 becomes Proposition 7.1, within the same document, things will change automatically. Is there any way to set things up so this will happen in Paper 2 when I move things in Paper 1?

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User the xr package (or xr-hyper), have a look at How to reference another document in LaTeX. – Stefan Kottwitz Apr 15 '11 at 22:34

You can use \label/\ref to external documents using the xr and xr-hyper packages.