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How does Lean Library identify legal Open Access copies of articles?
How does Lean Library identify legal Open Access copies of articles?

This article outlines our flow of identifying legal Open Access copies and explain how we find Open Access articles with Unpaywall

Clare Chan avatar
Written by Clare Chan
Updated over a week ago

When Lean Library extension identifies a DOI on a page, see here for how we do that, we will use this DOI to look for a legal Open Access copy of the article.

The services we currently use are, and these are exceptional and respected sources for this data.

How does the extension find Open Access versions of articles via Unpaywall?

On the occasion when you cannot access an article via your library holdings, we'll look for an Open Access version via Unpaywall and

With Unpaywall, our pop-ups specify the type of Open Access version in plain text. For example, the below Open Access version provided by our extension via Unpaywall is the "Published Version - Unpaywall":

The possible versions from Unpaywall are "Submitted Version", "Accepted Version" and "Published Version". This version classification is only available for content sourced via Unpaywall.

Below is an explanation of each version:

  • Submitted Version is not yet peer-reviewed.

  • Accepted Version is peer-reviewed, but lacks publisher-specific formatting.

  • Published Version is the version of record.

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