Do you know of a text--in English--whose treatment of the class number formula is based on the approach expounded by Zagier in sections II.8 and II.9 of the aforementioned book? Unfortunately, my command of the German language is not so good yet: to add insult to injury, it seems to me that Springer Verlag is still to commission a translation into English of this notable book.

Let me thank you in advance for your attentive consideration of this request of mine.