Section heading for references and the actual citations are squished together in LaTeX.

Question

This must be a common problem because I see it in many published papers but it seems to be quite tricky to google for. You can insert a bibliography like so

\bibliographystyle{plain}
\bibliography{foo}

and everything works as expected except there is sometimes (I have no idea what circumstances cause this -- it seems random to me) no space between the section heading (e.g., "7. References") and the start of the actual references. The section heading and first citation appear all squished together. It's not utterly egregious but seems to me to be unambiguously a flaw in the typesetting.

I've been putting up with it for years but someone somewhere must have noticed this and been obsessive-compulsive enough to track it down and figure out what causes it and how to correct it.

I thought this would be a good place to record the solution. Let me know if you can think of ways to make this more googlable.

ADDED: Here is an example document exhibiting the problem: http://yootles.com/outbox/squish/. (See also my workaround below.)

Answer 1

It turns out that LaTeX will sometimes remove the space between the References section header and the start of the actual references if it is trying to avoid having the document spill over to an extra page.

So one workaround is to either lengthen or shorten the document so it's not on the brink of spilling over to an additional page.

A related workaround (thanks to bluebrother's answer) is to explicitly tell LaTeX to allow the page with the start of the references a little extra vertical space (eating into the bottom margin slightly). That can be done with the following command right before the "\bibliographystyle{plain}":

\enlargethispage{\baselineskip}

Another workaround that seems to work:

1. Change to \bibliographystyle{amsalpha}
2. Recompile
3. Change back to \bibliographystyle{plain}
4. Recompile
5. (Don't recompile again or it will re-squish it.)

Answer 2

Not sure if that's the cause, but in case the bibliography can be fit on the page by removing that space you could try to use \enlagethispage{someamount}