If I understand correctly, the original source is this. I can't find any way to access it online, but everyone who talks about it says the results mentioned in that blog post and no one says otherwise, so I'm assuming they didn't just make it up.

I'm impressed. I took a look at various sources, and it seems like you can't even buy a used copy of that book anymore - it only exists in various academic libraries, and in many of them, it's stored only as microfiche/microfilm.