E-dissertations, articles and research works can be found in open repositories or digital archives (open access archive) of universities and scientific institutions. Most of the materials can be retrieved in full text format. Members of the institution can upload their materials into such repositories. The repositories may contain peer-reviewed articles, dissertations, historical documents, images, etc.
The global association of digital archives OAIster makes archival materials accessible through the worldwide union library catalogue WorldCat. A separate search form has been developed for searching among materials in digital archives that allows searching exclusively among the OAIster materials.
Advanced Search is best suited for this purpose
Fig. 1. OAIster search form.
If you do not limit your search from the very beginning, the database offers many options for narrowing your search results.
Fig. 2. OAIster search results.
The number of results is in the brackets after each limiting field. Results can be refined by the format, language, publication year, author, content (fiction / non-fiction / biography) and topic. Choosing the Open Access limiter in the beginning of the search or while refining the results will show you content from only known open access subdatabases, but for many of the results you get without this filter, links leading to full texts can be found when opening the record.
BASE is a multi-disciplinary search engine to scholarly internet resources. It provides more than 150 million documents from more that 7000 sources. Full texts of about 60% of the indexed documents are accessible for free (Open Access). BASE also discloses web resources of the "Deep Web", which are ignored by commercial search engines or get lost in the vast quantity of hits.
BASE search has lots of options for limiting or expanding the search. You can also use different languages for searching.
Fig. 3. BASE advanced search
The search results are displayed in a list, sorted by relevance. You can also order them alphabetically (either by author or title) or by date of publication. It is possible to refine the search results by author, subject, DDC, year of publication, content provider, language, document type, access and terms of re-use. If you filter by language, keep in mind that "unknown" language means that the language is just not specified - you can also find English language documents from there.
In the list you will see a short view of the record, for more information, click on Detail View. If you can not find a link to the full text from the BASE record, you can try checking in Google Scholar.
Fig. 4. BASE results view.
Please use BASE help page for more detailed information.
CORE also allows you to search digital archives of the world. In the basic search, operator OR is used as a default, meaning that at least one of the words is searched. In advanced search you can use different fields for different operators.
Fig. 5. CORE advanced search form.
You can refine your search by year, language, journals and repositories. A permalink for the search is also displayed under the refining categories. You can see more detailed information (bibliographic information, suggested articles and geographical location of the repository) about the record by clicking on its title.
Fig. 6. CORE results.
You might get less results with a CORE search, because CORE only searches for scientific publications. It is also able to find some smaller OA journals that OAIster and BASE miss.
DSpace is the digital repository of the University of Tartu. You can find its materials by searching on the webpage or using Google searches or the uppermentioned archives.
Fig. 7. DSpace main page.
Materials from the National Library archive Digar can be retrieved by separate archive searches or by links from the e-catalogue ESTER and ISE.