and Hitler's photographer Heinrich Hoffmann, an early art adviser who fell from Hitler's favor after 1941, due to Martin Bormann's dislike of him, but who had acted as an intermediary between some German art dealers and the Linz program, and possibly did the same in the Netherlands as well. Confiscated or bought? There is some debate about whether art for the Führermuseum was primarily stolen or purchased. Hanns Christian Löhr argues in Das Braune Haus der Kunst: Hitler und der "Sonderauftrag Linz" ("The Brown House of Art and the 'Sonderauftrag Linz'") that only a small portion of the collection – possibly 12 percent – came from seizures or expropriation. Moreover, another 2.5% was derived from forced sales. However, Jonathan Petropoulos, a historian at Loyola College in Baltimore and an expert in wartime looting, argues that most of the purchases were not "arm's length" in nature. Gerard Aalders, a Dutch historian, said those sales amounted to "technical looting," since the Netherlands and other occupied countries were forced to accept German Reichsmarks that ultimately proved worthless. Aalders argues that "If Hitler's or Goering's art agent stood on your doorstep and offered $10,000 for the painting instead of the $100,000 it was really worth, it was pretty hard to refuse." He adds that Nazis who encountered reluctant sellers threatened to confiscate the art or arrest the owner. Birgit Schwarz, an expert on the Führermuseum, in her review of Löhr's book, pointed out that the author focused on the purchases which were held in the Führerbau in Munich and ignored the deposits of looted art in Upper Austria in Thürntal, Kremsmünster and Hohenfurt/Vyssi Brod. On the subject of purchases versus confiscations, Dr. Cris Whetton, the author of Hitler's Fortune commented: I had expected to find that [Hitler] was directly responsible for looting and stealing of paintings that he wanted for himself, and I couldn't find any evidence of it, I found evidence that he paid for them; sometimes at knock-down prices, but not direct theft in any way. I was quite surprised by this, and I have to say in all honesty that's what I found. The Dutch Advisory Committee on the Assessment of Restitution Applications for Items of Cultural Value and the Second World War assesses sales by Dutch Jews to the Sonderauftrag Linz. At least two restitution claims were rejected because the Committee argued that there were not enough indications showing coercion