Many scientific journals, books and databases require a subscription and are thus behind the paywall. On this page, you will find resources that are freely available to all.
Tampere University Press (TUP) is an Open Access publisher of peer-reviewed academic books focusing on social and human sciences. TUP books are immediately openly available in the Trepo Repository and the OAPEN Library , for example, and are also indexed in the Directory of Open Access Books TUP does not collect Book Processing Charges for open access publishing.
Open Access repositories can be either institutional e.g Trepo or subject-based e.g. arXiv, RePec. Institutional repositories provide access to institutional research output and articles produced by the members of an institution or an university. Subject-based repositores focus on articles and other research outputs published in a specific discipline. You can find more repositories from these services:
What are preprint repositories
Preprint repositories contain scientific articles that haven't been peer reviewed yet. The repositories can be either subject based or multidisciplinary. They may also contain other additional material such as data associated with an article.
Many publishers and funders have also launched their own preprint repositories (e.g. F1000 Research, Gates Open Research, Lancet, MDPI, Peer J, Springer Natue, Wellcome and Wiley).