PDF rendering with invalid references

[davidjao]

So, I understand that http://planetmath.org/sheaf is broken for the same reason as previously reported in planetmath/12_Field_theory_and_polynomials#2

And I understand that the underlying issue seems to be hard to fix, and that even the suggested PDF workaround perhaps requires more effort than what we have available right now.

But can we at least get the PDFs themselves right? For example looking at page 3 of https://github.com/planetmath/54_General_topology/blob/master/pdf/54B40-Sheaf.pdf there are two incomplete references (??) (??) on the page. I can't imagine that this should be hard to fix, but I don't know enough about how the files are generated to do it.