But it’s not a huge problem actually: just link to the search page instead and let the user decide what they want to download.
I tried to automate downloading just a thousand books and it was unbearably slow, from IPFS or the mirrors both. I ended up picking the individual files out of the torrents. Even just identifying or deduping the top 100k would be a significant task.
collection “ia” → torrent “annas-archive-ia-acsm-n.tar.torrent” → file “annas-archive-ia-acsm-n.tar” (extract) → file “notesonsynthesis0000unse.pdf”
But probably you should get it from the database dumps they provide instead of hammering the website.
So you come up with a list of books you want to prioritize, search the DB for torrent name and file to download, download only the files you need, and extract them. You’ll probably end up with quite a few more books, which you may index or skip for now, but it is certainly doable.
I count 80+ editions of J.R.R. Tolkien's _The Hobbit_ at:
https://tolkienlibrary.com/booksbytolkien/hobbit/editions.ph...
granted some predate ISBNs, one is the 3D pop-up version, so not a traditional text, and so forth, but filtering by ISBN will _not_ filter out duplicates.
There is also the problem of the same work being published under multiple titles (and also ISBNs) --- Hal Clement's _Small Changes_ was re-published as _Space Lash_ and that short story collection is now collected in:
https://www.goodreads.com/book/show/939760.Music_of_Many_Sph...
along with others.
I wish there was some better book cataloging/organizing scheme --- the Online Books Page uses LoC:
https://onlinebooks.library.upenn.edu/subjects.html
and is the most workable of the indices I've used.
1. There’s a lot of variants of the same book. We only need one for the index. Perhaps for each ISBN, select the format easiest to parse.
2. We can download, convert and index top 100K books first, launch with these, and then continue indexing and adding other books.