It's from B.T.White's venerable old warhorse "Tanks and other Armoured Fighting Vehicles 1900-1918", the cover of which can be seen about halfway down this page:
I'd pretty much say that Peter's critique is spot-on. It's been long out of print, but secondhand copies always crop up (see either Abe Books, or www.bookfinder.com, with neither of which I am affiliated in any way!).
This weapon system was unvieled at the 1906 Berlin motor show, along with the Ehrhardt version.
The German military hiarchy was split regarding the appreciation of motor vehicles. Some of their decisions are baffling in retrospect. The Military Vehicle Inspectorate, for example, deemed four-wheel drive developement unnecessary and declined further funding in 1908. The logic being that a lorry should be operated only on good road beds; horses were completely satisfactory for anything off-road. Fortunately, the Artillerie Trials Board had a different vision, and ordered motorised anti-balloon investigative trials carried out from 1906.
Only one example of the subject vehicle was built; being replaced each successive year by an improved version until the Ehrhardt Model 1912 . This vehicle, along with a Daimler version saw a limited production run for the first time. However, it was the 1914 versions, mounting the 7,7cm BAKs, that saw appreciable production numbers, and widespread use in the Great War.