Picker, Tischgesprache, entry for 4th June 1942. That Hitler not only knew about the extermination measures but had repeatedly encouraged their speedier execution is today proved beyond doubt, in spite of still powerful popular prejudice ('If the Fuhrer had known that ...'). See for example Zoller, 'Hitler privat'; Dietrich, 'Hitler': The Goebbels Diaries; Carl Haensel, 'Das Gericht vertagt sich'.