French National Library
The data.bnf.fr project endeavours to make the data produced by Bibliothèque nationale de France (French National Library) more useful on the Web.
If you see a shield icon Insecure content shield icon appearing in the address bar (right side), you can click on this icon to download the insecure content. See details
The BNF PDFs do not seem to be easily accessible.
Here is an example to retrieve digital works from BNF ID in Wikidata.