LaTeX Coffee Stains (2009)
Some earlier research on this topic:<p><a href="http://arxiv.org/abs/0903.3365" rel="nofollow">http://arxiv.org/abs/0903.3365</a><p>and<p><a href="http://arxiv.org/abs/0812.3367" rel="nofollow">http://arxiv.org/abs/0812.3367</a>