Fixes #35 partly. Warning persists in included papers.

[santa-klaus]

see the issue for further information.

[frehage]

Thank you @santa-klaus for this solution. I have added the same solution to my own pull request #40, and also extended this solution with an addition that fixes the warning for the unnumbered parts of the papers. Since I am not part of the E2-phdcouncil any longer, I will leave the decision to merge the request to them (@MasoudBahraini).