Tootler: We are on the Internet. I can't give you documented evidence of anything, on this medium. No-one can.

That's a cop-out if ever I saw one. It is perfectly possible to list published sources which people can go and check if they wish, as someone did earlier with a reference to books by Stan Hugill, who is an accepted authority.

This is an informal forum and strict academic rigor is not looked for, but I suggest that a request for evidence should be treated seriously and not dismissed out of hand.

I am not arguing here about which theory is correct, but about demonstrating that your theory has a reasonable basis.