J. W. Backus. Letter to Ross. May 7, 1957.
J. W. Backus. Letter to Ross. May 7, 1957. 3 pages. Computer History Museum, gift of Dick Sites, access number 102655104. Part of Lot 58 of The Origins of Cyberspace auction, Christie's, February 23, 2005.Size 537.1 kB - File type application/pdf