Almost all universities today require that theses defended by their students have a digital version that is freely accessible. This overview of a few Western European countries presents national resources, raises questions of exhaustiveness, and shows the importance of foreign theses in broadening innovation and research. A full list, with over 140 links to the main repositories of Western European university theses, is published in BASES, no. 438, July/August 2025.
Scope and limits of our investigations
- Due to the large number of university sites now accessible, we (FLA Consultants) only considered theses defended in European universities.
- This list is limited to free access, knowing that the paid database Proquest Dissertations and Theses Global lists more than 6.3 million theses worldwide.
- We primarily searched for doctoral theses (PhD). Unfortunately, on some sites, these are mixed with master’s or even bachelor’s dissertations. We have indicated this whenever we became aware of it.
- Finding the access path to theses on a university site is sometimes difficult, which is why we have detailed each step whenever useful. Also worth noting: search tools for thesis corpora are often underdeveloped, even rudimentary.
- The presence of a thesis reference does not automatically mean it is available online (age, embargo, confidential thesis).
The figures indicated are those obtained during our searches carried out in August 2025.
The global view
Two disappearances
As a result of both the very rapid increase in the volume of theses to be indexed and the technical obsolescence of their respective platforms, two pillars of global thesis research disappeared within a few months.
DART-Europe e-theses portal closed on 3 February 2025, and Global ETD Search of NDLTD has been inaccessible for several months, leaving users waiting for a possible migration to a new platform. The latter recommends, in the meantime, the OATD site (https://oatd.org/), but unfortunately it regularly becomes saturated.
EBSCO Open: of little use for Europe
This site (https://opendissertations.org/) lists theses written in English. Many originate from the United States or Australia. For the United Kingdom, the source is clearly ETHOS, which was made inaccessible in 2023 due to a cyberattack. Thus, there are no English documents since that date, and for those before, access to the thesis is not possible because the link points to ETHOS. Furthermore, Ireland is not covered.
The new champions
Faced with this reshuffling of the cards, three players stand out:
- BASE: the new reference
The academic search engine of Bielefeld (https://www.base-search.net/) has several strengths:- Nearly 3.75 million theses among more than 435 million documents worldwide
- Ability to search by country and then by university
- Multilingual interface and effective advanced search
Drawback: it is not exhaustive, and duplicates are quite frequent.
- OPENAIRE: another universal search engine
(https://explore.openaire.eu/) offers more than 317 million documents, including nearly 2.6 million doctoral theses, slightly fewer than BASE, with the possibility to search by country and then by university.
Drawback: not all universities are covered. - CORE: the thematic approach
This site (https://core.ac.uk/) focuses solely on subject-based searches.
Instructions:
- Enter a term in the search box on the homepage
- Add AND document Type:"thesis" or click on "thesis" in the drop-down "Type" menu
Limitations: no sorting by country, very partial coverage, sometimes nonexistent for certain universities.
The European tour of theses
Austria: Alpine efficiency
More than 100,000 theses since 1990 are available on the Austrian library network site https://search.obvsg.at/primo-explore/search?vid=OBV, with bibliographic data and abstracts.
Access path:
- Erweiterte Suche ["advanced search"] on the right-hand side
- Choose Hochschulschriften ["university publications"] at the top of the table
- In the drop-down "Suchbereich," choose Dissertationen
Since the content is not exhaustive, it may be useful to supplement with university sites.
Top 3 Austrian universities:
- University of Vienna: 9,108 doctoral theses on https://utheses.univie.ac.at/# (click "Erweiterte Suche" for advanced search, then select dissertation under Thesis)
- Vienna University of Technology: 36,456 theses including master’s dissertations on https://repositum.tuwien.at/ (then "Theses" under "Browse by" on the left-hand side)
- University of Innsbruck: http://diglib.uibk.ac.at/ulbtiroloa, enter a term in the search box which opens a menu on the right where you can select either Thesis (diplom) 3,765 documents, or Dissertation (PhD) 2,497 documents.
Belgium: federal and regional solutions
Federal solution
UNICAT (Union catalog of Belgian libraries, https://unicat.be/) lists one million references of theses among other documents, not necessarily Belgian, located in many Belgian institutions.
Access path:
- Enter a search term or combination on the homepage
- Then select Dissertations in the "Resource type" menu on the right-hand side.
Each reference links to the originating institution and indicates which institutions hold a copy.
Regional solutions
- For Wallonia: Periscops (https://periscops.be), recently launched, lists, among other documents, 29,773 theses from French-speaking universities (Liège, Louvain, Namur, Mons, Université Libre de Bruxelles). Exclusively doctoral theses.
- For Flanders: it is more complex; we recommend using BASE or OPENAIRE (not for KU Leuven) as a complement to UNICAT. To go further, university sites must be consulted directly.
Denmark: Nordic diversity
Three complimentary sites:
- Research Portal Denmark (https://local.forskningsportal.dk/search/78730): 780,320 documents including 9,941 theses accessible via "thesis doctoral" in Publication Types. Several advanced search options available.
- DTU Findit (https://findit.dtu.dk): 31,524 theses (PhD and Doctoral), mainly from the Technical University of Denmark and other institutions. Registration required (free), then go to advanced search, select Thesis, and enter search terms. Results mix PhD and master’s theses.
- Aalborg University (https://vbn.aau.dk/): site only in Danish with documents unavailable elsewhere.
Access path: go to Publikationer, select d-afhandling (4,347 documents) and/or doktordisputats (102 documents).
The full document will be published in a special issue of BASES; subscribers can request it by email at contact@base-publications.com, and it can also be purchased on www.bases-netsources.com.
Note that Eastern European countries are covered in the longer version of this article.
France: French-style simplicity
470,660 theses listed on theses.fr (https://theses.fr/). Almost all French doctoral theses defended since 1985 are included. Bonus: 78,682 theses in preparation are also available.
Complementary alternative: HAL theses (https://theses.hal.science/) offers 167,595 theses in full text, but only those voluntarily deposited by authors, hence the difference in numbers with the previous site.
Germany: the champion of historical referencing
The German National Library lists 1.327 million references, in principle all theses defended since 1945, in both paper and electronic formats.
Access path: go to https://portal.dnb.de/opac.htm / choose Erweiterte Suche ("advanced search") / in the drop-down menu "Schlagwörter" ("keyword"), select "Hochschulschriftenvermerk" ("thesis notes") / enter "diss?" as a criterion in this line / complete with search terms.
Useful reference: Annette Schläfer’s excellent note "Finding theses in Germany" [June 26, 2013, updated in 2023] remains relevant for further exploration: https://germano-fil.hypotheses.org/1697.
Why should information professionals be interested in theses defended in other countries?
This type of search is often neither spontaneous or common practice. However, consulting these works offers many advantages.
- Experts on a particular subject are not found only in one country. Following the work of the best experts, regardless of their location, allows you to broaden your perspective.
- A doctoral thesis often represents the first formalization of a research project, sometimes before the publication of an article or its international dissemination. Therefore, paying attention to them offers the opportunity to identify innovations at an early stage.
- Theses can provide local data or employ methodologies specific to the country in question, which enriches our understanding and opens up new avenues for research.
- Analysing the origin of doctoral theses in a specific field can reveal opportunities for collaboration with international research teams or institutions.
- In the context of a prior art search for a competing patent, a thesis, as the first milestone in an innovative process, may contain elements that appear very early in the process.