Mss.B.B61_W

Warburg, Felix M.: To Boas. 1933 July 3

Warburg, Felix M.: To Boas. 1933 Oct. 5

Warburg, Felix M.: To Boas. 1934 June 11

Warburg, Felix M.: To Boas. 1935 Feb. 14

Warburg, Felix M.: To Boas. 1937 Feb. 19

Warburg, Felix M.: To Boas. 1937 Mar. 24

Warburg, Ingrid: To Boas. 1939 Jan. 4

Warburg, James: From Boas. 1941 Dec. 19

Warburg, Max: From Boas. 1920 Nov. 16

Warburg, Max: From Boas. 1930 Oct. 9

Warburg, Max: From Boas. 1931 Jan. 27

Warburg, Max: From Boas. 1933 Dec. 29