Keenious finds its articles in the open source, nonprofit-run OpenAlex database of academic works. Here is how OpenAlex describes the contents of its database:
We index over 250M scholarly works from 250k sources, with extra coverage of humanities, non-English languages, and the Global South.
We link these works to 90M disambiguated authors and 100k institutions, as well as enriching them with topic information, SDGs (sustainable development goals), citation counts, and much more.
OpenAlex indexes articles, books, datasets and dissertations, but because the AI in both OpenAlex and Keenious does not have access to the full text of books, and books do not usually have freely available abstracts as articles do, the ability of these AIs to create "on-the-nose" topic analysis of books is limited. By default, Keenious' ranking algorithm favors journal articles with DOIs, but the only OpenAlex content Keenious completely excludes are articles marked as "retracted" in the OpenAlex database.
For more about what OpenAlex includes plus a comparison between OpenAlex and scholarly searches like Scopus and Dimensions, see: https://openalex.org/about
