sympy/sympy — pull request #1689 by nthorne (2012-12-05 21:27:02+00:00)
Title: Found missing paper on new uni.

I took a quick look at the repo you mentioned in your comment on commit 974380a and apparently the prof had changed uni, and had the paper available at his new location (link found within fredrik-johanssons repo), so I wen't ahead and added the updated references. Sorry for not spotting that one directly.