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Resources for Grey Literature

Trial Registries - Primary Resources

Online trial registries may include results of completed but unpublished clinical trials. These resources can be helpful in identifying otherwise unreachable trials and provide additional details of published trials. Many individual drug companies also have posted trial registries on their websites, although their quality varies. Even without results, knowledge that the trial exists can be helpful for reviewers, because they can contact the principal investigator for more information.

Trial Registries - Additional Resources

If further information is requested, these are additional resources to consider: