Add spaces between the words in the following text: HehadbeenanassistantofEichmann's,butwasinfactaratherstrangepersonintheserviceofAmericanIntelligencewhohadwrittenseveralbooksunderthepseudonymofWalterHagen.HoettlalsoworkedforSovietespionage,collaboratingwithtwoJewishemigrantsfromVienna,PergerandVerber,whoactedasU.S.officersduringthepreliminaryinquiriesoftheNurembergTrials.
He had been an assistant of Eichmann's, but was in fact a rather strange person in the service of American Intelligence who had written several books under the pseudonym of Walter Hagen. Hoettl also worked for Soviet espionage, collaborating with two Jewish emigrants from Vienna, Perger and Verber, who acted as U.S. officers during the preliminary inquiries of the Nuremberg Trials.