Very little repository content can be found with Summon (SIA's search engine). However there are four specialist repository search engines. There is much overlap between these services, and at present (2024) it is not clear which is best. They are:
There are several other options:
It is also possible to search an individual repository. Each repository will be structured differently, and have different search options. Some universities have separate repositories for research papers published by staff on the one hand and dissertations and theses on the other. Some also maintain specialist repositories for certain collections of material. If you the repository you want is not in the list linked to above, you can usually find it by searching the website of the institution concerned. University repositories are usually accessed via the university website. See the next tab of this guide for a few suggested repositories.