Instruct: Classify the given Amazon review as either positive or negative.
Query: Must have for flying wing followers.

This is the book that is written by the man himself, Reimar Horten. It give specifications for all of the planes the brothers built from 1933-1960, and talks about the problems they encountered, and their solutions. I need to learn German because not all of the book is translated. It is an eye-opening look at the work of two geniuses. Jack Northrop wasn't in the same league as these guys.