Photocopies of various items of material considered of special relevance to reseach at NBA, received more or less arbitrarily. Includes: 1) Bohr, Harald - Erich Hecke correspondence, 1920-1937. Gift from Hans W. Praetorius. 2) Bohr, Harald - Richard Courant correspondence, 1930-1933, 1937 (Copies from originals in Courants old house in New Rochelle. Copies provided by Courant's son, Ernest in 1983.); 1945-1952 (Copied from originals in Courant's files in the Courant Institute of NYU). Material deposited by Asger Aaboe. 3) Franck, James - Hilde Levi correspondence, 1935-1961. Copies of originals donated by Hilde Levi to University of Chicago. 4) Heiseenberg, Werner to Hendrik Anton Kramers, 1947 (Source unknown) 5) Hulthen, Lamek - Wolfgang Pauli correspondence, 1943-1947 (Gift from Hulthen) 6) Klein, Oskar - Yoshio Nishina correspondence, 1928-1929. Memoir (OK) 1975. Copies from Nishina Memorial Foundation. 7) Oppenheimer, Robert to G. Uhlenbeck, 1926-1934 (Source unknown) 8) Pauli, Wolfgang to Hendrik Anton Kramers, 1935-1938, 1951 (Source unknown) 9) Schrd̲inger, Erwin to Wilhelm Wien, 1925-1927 (Source unknown).