I read this book in English, but it was originally written in German.
Being a teacher my self for 20 years I thought I knew pretty much everything when it comes to didactics and classroom management. However, this book really made me (re-)think about teaching in new ways and it is a book I strongly recommend to anyone who is a teacher, or even better, who wants to be a teacher. There are really useful "hands on" examples and personal exercises in the book mixed with classic university theory. I wish I would have had this book when I took on my first class 20 years ago, but better late than never, I guess.