"

Navenby 

Cheers for the message - you might be 'the hard part,' but I actually enjoyed re-doing some of the refs! Good old books, you forget how useful they are sometimes! I guess Google has made me lazy... Thankyou, once again, for your patience in going through all 120-odd refs. It was much, much appreciated. Next time I write something, I'm going to choose a subject with three sources (reliable of course) and nothing else!'''''' "