Do you know of a text--preferably in English--whose treatment of the class number formula is based on (or follows closely) the one expounded by Zagier in sections II.8 (binary quadratic forms) and II.9 ($L(1, \chi)$ and the class number) of the aforementioned book? Unfortunately, my command of the German language is not so good yet and, to add insult to injury, it seems to me that Springer Verlag is still to commission a translation into English (or one of the Romance languages) of this notable book. 


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


**BOUNTY!** [Jan-Christoph Schlage-Puchta](https://mathoverflow.net/users/37555/jan-christoph-schlage-puchta) suggests chapter 6 of H. Davenport's "Multiplicative Number Theory" as an alternative text for this topic. Though, I must confess that the fact that Davenport dedicates only two or three lines of the chapter to Lagrange's main result on reduction of binary quadratic forms makes one feel uneasy right from the start. So, if you are proficient in German and wish to provide a translation of pages 64-68 of Zagier's book, I will really appreciate your help and award you the **bounty** I am herewith offering on this question.



Don Zagier's "Zetafunktionen und quadratische Körper"
here is my "screenshot translation", hoping it is sufficient for your purpose:


* [page 64](https://ilorentz.org/beenakker/MO/Zagier_64.png)
* [page 65](https://ilorentz.org/beenakker/MO/Zagier_65.png)
* [page 66](https://ilorentz.org/beenakker/MO/Zagier_66.png)
* [page 67](https://ilorentz.org/beenakker/MO/Zagier_67.png)
* [page 68](https://ilorentz.org/beenakker/MO/Zagier_68.png)


please correct me if I have misrepresented any technical term.


