Beginning before the German surrender and continuing for the next two years, the United States pursued a vigorous program of harvesting all technological and scientific know-how as well as all patents and many leading scientists in Germany (known as Operation Paperclip). Historian John Gimbel, in his book Science Technology and Reparations: Exploitation and Plunder in Postwar Germany, states that the "intellectual reparations" taken by the U.S. and the UK amounted to close to $10 billion.[8] German reparations were partly to be in the form of forced labor.