Proceedings Citation Guide

Open Access Proceedings: How to Find and Reuse Them

Many proceedings papers can be read for free, but free to read is not the same as free to reuse. This guide explains the main open access routes and how to find legal copies.

Last updated 6 November 2026

On this page
  1. What open access means for proceedings
  2. Gold, green and diamond routes
  3. Finding a legal free copy
  4. Preprints and repositories: what they are and are not
  5. Reading licences before you reuse
  6. Citing an open access version
  7. Common mistakes
  8. Frequently asked questions
  9. Sources and further reading
  10. Related topics

In brief

  • Open access routes are usually called gold, green and diamond; the labels describe who publishes and who pays.
  • Unpaywall and CORE help locate legal open copies; they do not host or grant rights themselves.
  • CEUR-WS.org describes itself as a diamond open-access service; its licence is set per volume.
  • Always read the licence line before copying text or figures.

What open access means for proceedings

Open access (OA) means that readers can get the full text without paying or logging in through a subscription. For proceedings, this matters because many workshop and conference volumes sit in a publisher library, in a society archive, or on a small hosting service.

OA has two separate parts. The first is access: can you read the paper? The second is reuse: may you copy, adapt or redistribute it? A licence, such as a Creative Commons licence, answers the second question. A paper may be free to read yet still restrict reuse.

This site gives general information only. It is not legal advice, and rules differ by publisher and country.

Gold, green and diamond routes

The three common labels describe where the open copy lives and who covers the cost.

  • Gold OA. The publisher makes the final paper free to read, often under an open licence. Authors, institutions or funders may pay a fee.
  • Green OA. The author deposits a version of the paper in a repository, such as an institutional repository or a preprint server. The publisher's policy decides which version and when.
  • Diamond OA. The paper is free to read and free to publish. Neither readers nor authors pay.

CEUR-WS.org describes its own service as a diamond open-access publication service. OpenReview states that papers are free to read and to submit, and arXiv states that submission is free. These statements come from the services' own pages. Terms for a given paper can still differ, so look at its record.

For the names of paper versions, read Preprints, Accepted Manuscripts and Versions of Record.

Finding a legal free copy

Work through these steps in order. Stop when you find a copy you may legally use.

  1. Check the publisher page. Look for an open access label or a licence line near the title.
  2. Check the hosting service. Services such as the ACL Anthology and PMLR publish volumes online. The ACL Anthology states a Creative Commons licence by date range.
  3. Search by DOI with Unpaywall. Unpaywall is an open database, API and browser extension run by the nonprofit OurResearch. It points to legal open copies found in repositories, preprint servers and publisher sites. It does not host papers itself.
  4. Search CORE. CORE is an aggregator of open access research, run by The Open University and Jisc, with an API for programmatic access.
  5. Search your institution's repository. Authors often deposit accepted manuscripts there.
  6. Look for a preprint. A preprint on arXiv or Zenodo may exist. Treat it as a different version until you compare it.
  7. Ask the library or the author. Many authors will share a copy they have the right to share.

Never use sites that distribute papers without the rights holder's permission. They can serve altered files, and using them may breach licence terms.

Preprints and repositories: what they are and are not

A preprint server hosts manuscripts before or alongside formal publication. arXiv, for example, states that it moderates for fit and scholarly value but does not peer review. A deposit in Zenodo is a general research deposit. Zenodo states it accepts open, closed and embargoed content, and that it registers DOIs through DataCite.

These services are useful for access. They are not a guarantee that the text matches the published proceedings paper. Pages, figures and even results can change between versions.

If a final version exists, prefer it for citation unless your instructor or venue says otherwise. If you cite a preprint, name the server and the identifier. Zenodo explains that each new version is a separate record with its own identifier, so a cited version stays fixed.

Reading licences before you reuse

Find the licence line on the paper's first page or its record page. Typical items to look for:

  • A Creative Commons name and version, such as CC BY 4.0.
  • A statement that copyright stays with the authors.
  • A statement that republication needs permission.

Under CEUR-WS.org's published terms, copyright for individual items rests with their authors or owners, the licence is given in each volume's index file, and republishing needs permission. The ACL Anthology states that third-party material in its pages needs permission from the owner. Such statements show why you should check the exact volume or paper, not the service in general.

For quoted text, short quotation under your citation style is normal. For figures and tables, check the licence before you reproduce them. More background is in Copyright and Licences for Proceedings Papers.

Citing an open access version

Cite the version you actually read, and give the most stable identifier it has. Use the DOI when one exists. If the open copy is a repository deposit, give the repository name and its identifier.

A fictional example of a repository deposit, in a simple author-date form:

Doe, J., & Roe, R. (2023). An example title of a fictional workshop paper [Preprint]. Example Repository. https://doi.org/10.0000/example.2023.1

Do not add an open access label to the reference unless your style asks for one. Where the link may disappear, see Link Rot: Archiving the Web Pages and PDFs You Cite.

Common mistakes

  • Treating free to read as free to reuse.
  • Citing a preprint as if it were the published paper.
  • Trusting a mirror site over the original host. CEUR-WS.org states that mirroring its site is prohibited, so use the original.
  • Copying figures without checking the licence.
  • Assuming every OA copy is peer reviewed. Review status depends on the venue, not on the access model. See Workshop Papers vs Conference Papers.

For a list of other frequent errors, see Ten Common Mistakes When Citing Proceedings.

Frequently asked questions

Is open access the same as peer reviewed?

No. Access model and review process are separate. Check the venue's own description of how papers were reviewed.

What is diamond open access?

It is a model in which papers are free for readers and free for authors to publish. CEUR-WS.org uses this label for its own service.

Does Unpaywall host the papers it finds?

No. It points to legal open copies held elsewhere, such as repositories and publisher sites.

Can I reuse figures from an open access paper?

Only as the licence allows. Read the licence line, and ask the rights holder if it is unclear.

Which version should I cite?

Cite the version you used. Prefer the final published version where it exists and you have checked it.

Sources and further reading

  1. CEUR-WS.org — CEUR Workshop Proceedings (2026)
  2. ACL Anthology — ACL Anthology FAQ (2026)
  3. arXiv — About arXiv (2026)
  4. OpenReview — About OpenReview (2026)
  5. CERN / Zenodo — About Zenodo (2026)
  6. Zenodo — Zenodo records and versioning (2026)
  7. PMLR — Proceedings of Machine Learning Research (2026)