This book is about the Nimzo-Indian Classical line 4.Qc2 (also known as the d2-line, for which basically I could not find an established name. As far as I know, the 4.Bd2 line has never been covered in such a comprehensive way in any book before. In the text I suggest that this line should have the combined name of Tartakower-Duchamp line because Tartakower played it often, while to my surprise Marcel Duchamp (who was also a famous French artist) played it too in the 1930s and indeed in a very good positional fashion against strong players.  Some of those games are in the book. Now this line enjoys greater popularity than ever before. About the Classical line with 4. Qc2 there is nothing much to add, except for the fact that it has become hugely popular, but unfortunately from my point of view it involves too much engine-style chess.