We are very grateful to the following individuals for their help: Barry Worrall, Steve Swain, Tim Wesson, Robert Whiston, Richard Oppenheimer, John Knight, Steve Stevenson, Patrick, and Stan Hayward. There is much information that has arrived on the internet and thanks are also due to these individuals who are too numerous to mention. We are also grateful to UKMM for much of their information used in the discrimination section.