this is of interest only for those who understand German -
It has been mentioned before, Ulrich Bruckner, head of our beloved Koch Media, has published a book on paghetti western that - judging from the sheer size of the book - looks like it's THE essential book on the subject in German.
http://www.amazon.de/Leichen-mehr-Italo-Western-seinen-Anf%C3%A4ngen/dp/3896027050/ref=sr_1_2?ie=UTF8&s=books&qid=1235138105&sr=1-2It's entitled "Für ein paar Leichen mehr - der Italo-Western von seinen Anfängen bis heute" ("For a few corpses more - the italo-western from its beginnings til today".
A second, revised edition has just been released, its 750-pages strong!
Judging from the excerpt that was included in Koch's Sollima-Box set, it's got to be nothing less than brilliant! I haven't got it as yet, but somebody promised it to me as a birthday gift, so I'm waiting....