I used to use thepiratebay.org, but recently it seems the quality of the site has degraded.
I sometimes also use 1337xx.to , but that site seems to have a very small selection.
Note that I couldn’t find an answer to this question in the wiki + meathread, so if the answer is already there, please direct my attention to it 🙏🏴☠️
Bitsearch is a good indexer for finding torrents from across multiple sites, but check the source as best you can, and then use a VPN and scan the files after.
https://www.bitsearch.to/search?q=pimsleur+dutch
You can also search in qbittorrent with the search plugin, it’ll be easier to see the sources from there.