New Book on Writing with a Zettelkasten (amazon.com)

Took four years hanging with the zettelkasten community, looking at the system from every angle, in the hopes of answering as many questions and clearing up as many confusions as I could. This book is the result of that work. In the end, I tried to write a book people would feel confident recommending. Hope you enjoy.

Nice! So is it based on physical paper notes, or (also) on digital tools? This is not obvious from the description…