"3 letters"@en . . "Correspondence with Dukas, Helen"@en . . . . . . . . "Helen Dukas (1896-1982) was the secretary of Albert Einstein, and later his biographer."@en . "WL3000/9/1/357" . . "The letters concern the dating of a planned but not delivered speech by Albert Einstein. Contained is an English translation of the original German typescript."@en . . . "This material has been digitised. Readers should book a reading room terminal to access it."@en .