Where do you find audiobooks?

I tried a couple of times to find certain audiobooks, but seldomly had luck. There just does not seem to be a place that sells digital versions of audiobooks, similar to how bandcamp sells music.

And even putting on my eye patch and throwing out my fishing net I was not able to find a place to get them.

I do not want to use a subscription service, especially if it's part of amazon.

Therefore it seems buying a CD and ripping it is the only option left.