Timber Framers Guild Forums General General Forum Questions Best English-language reference on Fachwerk?

Hello all. I am curious to know if there is anyone out there who knows of a good book on the "how and why" of German timber framing practice, written in the English language. If so, I would be grateful to receive title and author or ISBN in a reply. Failing that, is there a profusely illustrated book on the topic written in German that I can muddle through based on the photos and drawings? I'm looking for a technique book more than a picture book. Thanks!