Amazon use an independant resource, Neilsen Book Data, for any book not in their 'best seller' stock list, so it appears they have everything. They then, because of their buying power, beat the supplier down to low margins. If they can't, the book is effectively blacklisted on the site (the Amazon search engine 'cannot find it').
Amazon is convenient, but please support proper publishers where possible (especially in aviation where sales are relatively low), so we get more books like JFs.
I have e-mailed my son with the Flyer web page, e-mail headed 'Christmas is coming'.