Very concrete, very affordable although it is not professional, the book gives good tracks, with examples where everyone can meet. The challenge is always to translate what is said in reality. But of all the books read on the subject, it is the one that convinced me the most. No unnecessary talk, or incomprehensible, ridiculous or naive. I intend to try other works in the collection because I find them really well. The subdivisions are clear at the end of each chapter there is a summary + exercise. Really good!
