Tschichold in the 1920s was a pioneer of incredible, beautiful asymmetrical typographic based layouts, an literally wrote the book on this new style, called The Neue Typography (here's a PDF). And then, he rewrote the book on classical symmetrical typography too. Master.
I don't have that (The Form of the Book) for obvious reasons. Nor a PDF ...yet.
Back in a dusty design studio at art college there was one slim, battered book we conspired to keep out on loan from the library at all times, on rotation between us. It was the Ruari Mclean biography of Tschichold and perfectly covered the modernist work from the 1920s and the return to classicism of 1940s into Penguin and beyond.
But, I didn't buy that book. This is a massive Thames & Hudson volume, with a deeper and wider spread of work, stuff I hadn't seen elsewhere or in good quality large reproduction. It is a monster design book, even the ink density seems be higher than many others I've seen. Bravo.
It's not even that expensive on Amazon new or used.