ISNB is 0-85418-188-1; that should be all they need to know (though the right title helps!) As I mentioned, though, I don't think that it's going through the commercial distributors, so it will probably be quicker to order directly from EFDSS (contact details available through several links earlier in this thread). On the other hand, if Waterstones receives enough specific requiries it may feel obliged to carry some, which would make a change from all those books about jazz they stock and never seem to sell.