Together 2 pages, 4to, each with original envelope addressed in Einstein's late, shaky hand, postmarked and stamped." /> EINSTEIN, ALBERT. Two autograph letters, one signed ("Papa"), one unsigned, to Hans Albert Einstein, Princeton, 11 May and 28 December 1954. <I>Together 2 pages, 4to, each with original envelope addressed in Einstein's late, shaky hand, postmarked and stamped</I>. | Christie's