Ways to Open Access

Ways to Open Access

Frequent questions


Ways to Open Access

The Budapest Open Access Initiative established two routes to open access: The golden route:  publication in Open Access journals;The green route: archiving or filing works in Open Access repositories.

  • The golden route: According to the definition of Open Access, an open access journal can be accessed without payment being involved. Neither the reader nor the author pays to read or publish the work. However, there are many examples of Open Access journals where the reader can access content for free but the author or publishing organisation pays to do this. Many of the large scientific publishers have developed a hybrid publishing model in which one single journal can feature open access articles together with articles that must be paid for. These publishers offer authors the option of paying to publish their work in return for their article being made available through open access.This option is known as open choice.
  • The green route: open repositories are an alternative method of publication and scientific communication based on international open access initiatives. These include journal articles, presentations, book chapters and any other type of scientific publication in digital format. These are accessible online and often in their complete form.

What are repositories?

The main objective of repositories is to gather, archive, preserve and share the scientific and academic output of an institution in open access. This facilitates access to, and raises the visibility and dissemination of, the works that are deposited.

Works deposited vary depending on the type of repository. They can include doctoral theses, journal articles, conference communications, teaching materials including primary data from research and any other form of scientific publication and academic/institutional production in digital format

These digital archives generally list the “preprint” or “postprint” versions of documents prior to their publication:

  • ”Preprints” are the original version of a document before it was peer-reviewed and before it was accepted for publication.
  • ”Postprints” are the final version of a document that has been peer-reviewed and that incorporates suggested corrections and changes. This will be the final version accepted by the publisher.

Infograph: benefits of publishing in CRUE repositories

What type of repositories exist?

  • Institutional repositories: these are linked to specific institutions and store, maintain and share scientific, academic and institutional production.
  • Thematic or disciplinary repositories: these contain resources and documents relating to a specific discipline or subject area.
    • Arxiv: for mathematical science, physics, computer science, biology, finance and statistics
  • Data repositories: these repositories are for storing, sharing and protecting research data.
    • European Union open data portal a single access entry point to a large variety of data generated by educational institutions and other EU organisations. This repository enables individuals to use, reuse, link to and redistribute data without charge for any commercial or non-commercial purpose.
    • Zenodo: developed under protection of the OpenAIRE project and CERN, this repository compiles and shares multi-disciplinary research data from any scientific community, researcher or research institution.

How to find repositories

  • International ranking of repositories
  • Directories of repositories: these provide organised access to repositories.
    • OpenDoar: Directory of Open Access Repositories
    • Roar: Registry of Open Access Repositories
  • Search for repositories
  • Collections of repositories: these enable you to search through and access materials and resources from all of the repositories covered, simultaneously and using a single interface.
    • OAIster: union catalogue providing millions of records of open access resources. This catalogue was created by compiling material from open access collections from all over the world. OAlster currently has over 50 million records representing digital resources from over 2,000 collaborators.
    • OpenAire: Open Access Infrastructure for Research in Europe. An online repository infrastructure which aims to support the application of open access to science in Europe.
    • Recolecta: lists and provides access to scientific documents provided in open access format in Spanish institutional repositories.
    • Hispana: collection and directory of digital resources from archives, libraries and Spanish museums managed by the Ministry of Culture.

What is the embargo period to publish in a repository?

The embargo period is the period during which a publisher reserves the exclusive right to allow public access to a work or document after its publication.

The length of an embargo period varies depending on the journal or publisher, but usually it goes from 6 to 24 months. During the embargo period, which begins with the formal publication date, the full version of the document may not be accessible through a repository.

Once the embargo period is finished, the repository may publish an open access version of the document agreed upon with the publisher, usually the postprint.

Tools for finding the embargo periods of publishing houses and journals

In order to include documents that have already been published with a publisher in an open access repository, it is essential to be familiar with the publishing policies and copyright rights that govern the published content.

For this purpose, both national and international websites have been created.


Sherpa-Romeo: international website that compiles the author rights policies and self-archiving policies the main publishers and journals around the world. It includes information on the version or versions of the document that may be published on an open access basis and on applicable embargo periods.


Dulcinea: Spanish website that compiles the publishing policies of Spanish journals regarding access to their archives, exploitation rights, and publishing licenses. It includes information on the version or versions of the document that may be published on an open access basis and on applicable embargo periods.

Other Open Access resources

  • Hedatuz: digital library of Basque culture and science
  • Dialnet: joint project with a key focus on increasing the visibility of Hispanic scientific literature. It consists of journal articles, books, articles from joint volumes, conference proceedings, doctoral theses and so on. It also provides a referencing alert system and a repository which provides access to Hispanic scientific literature in complete text format.
  • Digital.CSIC: open-access scientific repository of the Higher Council for Scientific Research (CSIC)
  • DOAJ: Directory of Open Access Journals
  • DOAB: Directory of Open Access Books
  • REDALYC:initiative driven by the Autonomous University of the State of Mexico, providing open access to scientific production in Latin American journals
  • Europeana: European digital library, providing open access to more than 45,000,000 materials from more than 2,300 European institutions.