FFD,
I had exactly the same problems as you with amazon. but persavere with them and your book will come. Mine did!! I tried all over London, Foyles, Waterstones etc but to no avail as the book is only an american print.
You could also try the place where I done my ADX Knowledge test in the UK - American Air training in Norwich airport.
Do as no-sig says and try an internet search. Failing that goto the sheffield web-site. you can down load QandA from the ADX exam and also I think they give contact details from where to obtain the book.
Hope this helps!!
Good luck with your studies. I went to Sheffield Jan 03 an excellent place good people! you'll enjoy it!
WTD