I am writing a text on the Theory of Computation. I am looking for a photo of the mathematician Wilhelm Ackermann. He is well-known in the field, was a student of one of the most famous mathematicians of his time, and developed the important Ackermann function. So he is reasonably prominent in the history of mathematics in the early to mid 1900's, and I'd expect there to be a number of high quality pictures.
But there seems to be only one picture available (it is in the Wikipedia article linked-to earlier). It is terrible quality-- it looks like a photocopied high school yearbook, although I don't actually know where it comes from-- and I don't think even his mom or wife could like it.
Does anyone know of another? My text is Freely available, so I need it to be free of license restrictions, but after all this time I can hope that licenses are not a problem anyway.