You can find free #PublicDomainEbooks really easily using switching.social's eBook search page:
https://switching.social/public-domain-ebooks-search/
The search covers a wide variety of public domain sites, and includes many different languages.
@switchingsocial your search misses ebooks.qumran.org with 9.000+ (currently 9110, but in an hour probably more) plus ~1.000 EN free DE epubs which are either PD or CC
@switchingsocial w