There are so many, and I've got loads of them, so I'll check tonight. One's called 'Spirit of Milan', while my mate bought me a beautiful two-volume job with a slip case that covers cars right up to the 156, IIRC. One volume logs all the models Alfa ever made, the other volume charts the company's history. It's great to pour over the b&w pictures of Alfas in the 1930s etc, looking at the country, the Alfa factories the people and how they have all developed.
The only problem with single marque books, is that the authors tend to be blinkered and you have to read some of their gushing praise with tongue in cheek. The same is true of a Mercedes book I bought last month; that aside, they're all good fun.
Try and get one called Car Men - a series of books about great car designers. One book charts Walter de silva's work, covering the 156/166 etc; the translation is a bit hammy in places, but it is an interesting read re: 156 design ethos/Alfa design ethos.