This tool lets you search for free public domain eBooks on many sites in many languages all at once. Just enter the author, title or keywords you are looking for:
WHICH FILE FORMAT?
If you’re unsure which eBook format to download, generally “ePub” works on everything except Kindle, while “Mobi” works on Kindle.
“PDF” and “HTML” are best viewed on computers. “TXT” works on everything but may not look as good.
HELP! WHERE ARE THE eBOOKS ON WIKISOURCE?
To download an entire eBook instead of just one chapter, go to the contents page for that book and click on the download link there.