If it's worth saying, but not worth its own post (even in Discussion), then it goes here.
Notes for future OT posters:
1. Please add the 'open_thread' tag.
2. Check if there is an active Open Thread before posting a new one. (Immediately before; refresh the list-of-threads page before posting.)
3. Open Threads should be posted in Discussion, and not Main.
4. Open Threads should start on Monday, and end on Sunday.
Oops, indeed.
"citation needed"
Here is a quick-n-easy example, or if you want details they are here.
Here are a couple of books
And here is a long, detailed post with a lot of numbers, graphs, and references.