Can I upload the publisher’s PDF version of the work by another author to Moodle?
Answer
If the work is in the public domain, the PDF can be freely uploaded. Even though a work is in the public domain, some versions of it might belong to third parties, such as editors, translators, or the publishers themselves, or vendors in the case of PDF files available on Library databases.
If the PDF is published under an open license (such as Creative Commons Licenses), it can be uploaded.
When in doubt, it is always preferable to link to the original source, thus avoiding uploading files.