There are several web-based sources that you can try (below) to get a copy, some providing immediate access if the thesis you need is not on EThOS.
Dart-Europe E-Theses Portal
Allows you to search for theses from Universities in 16 European countries, the majority of which are available for immediate download.
Trove –the National Library of Australia’s discovery website.
[This help page gives you tips on how to find Australian theses: https://trove.nla.gov.au/blog/2020/05/08/australian-theses]
A portal to find Canadian theses and dissertations. Participation is voluntary, but around 25% of entries are available for immediate download.
An initiative of the Centre pour la Communication Scientifique Directe that aims to provide access to doctoral theses submitted to French universities and colleges.
The South African national e-theses portal.
This service from the principal provider of US theses is specifically limited to doctoral theses that are available as open access.
Networked Digital Library of Theses and Dissertations
The NDTLD site is an excellent starting point for tracing the existing of online theses from around the world. As well as a search, it also maintains a directory of links to other key websites. To search, click on the ‘For Researchers’ box.
If you are still unable to find the thesis you need, the Inter Library Loan service may be able to obtain it for you. Place a request using the British Library Loan Request Form available after clicking on Requests on the Primo home page and signing in. In the ‘Publisher’ box you must enter Thesis level and University,e.g.: PhD, University of Plymouth. Failure to provide this information may lead to your request being declined.
Please contact the Inter Library Loan Team for further advice or help.