Who is the copyright holder of a PhD thesis published in ProQuest? I have a Ph.D thesis obtained from ProQuest. I would like to reuse some of the figures from it in my own work.
Every page of the PDF contains this message on the bottom:


  Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.


How can I find out who is the copyright owner? It is not listed anywhere in the PDF, and I can find nothing useful on ProQuest's website.

The thesis is from the 70s, and the author has not been academically active since then. Tracking him down seems unlikely.
The original author is probably the copyright holder.

Two other options: it is possible that it is the university/research institute (see, eg, this MIT policy for an example) but this is relatively unusual; alternatively, if it was done with industrial sponsorship, the company might own copyright. If either were the case, though, I'd expect to see some kind of indication on the thesis itself. Absent a clear hint (eg an existing university policy, a commercial-looking funder) that someone else would hold copyright, I'd work on the assumption it's the author.

You can try and trace them - this is not quite as impossible as it sounds, as the university alumni office may well have contact with them and be able to pass on a letter. If you have tried and failed, you might still have the option of using them without permission and an apologetic footnote...