Berti and Gonard's book on the Visconti-Sforza tarocchi deck is quite different from Dummett's The Visconti-Sforza Tarot Cards.
Dummett's book includes large colored photographs of the cards with minimal (but fascinating) historical commentary -- the cards as art.
Bert and Gonard's aim is quite different. Although they provide another historical introduction to the cards, they are explicitly attempting to offer the reader a way to use the Visconti deck for modern divinitory tarot readings (even though the deck pre-dated the use of tarot cards in this way by 300 years). They offer smaller black and white idealized renderings of the cards with accompanying analysis of each card, mostly of an historical and visually descriptive nature, but with some explicit guidance for interpretation.
There are unquestionably better books out there for detailed guidance about using the tarot, but the authors' historical perspective is always informative.