National Security Action Memoranda Number 50: Official Announcements of Launching into Space Systems Involving Nuclear Power in Any Form. May 12, 1961.
05/12/1961
The Papers of John F. Kennedy , Presdiential Papers, National Security Files, Meetings and Memoranda Series, National Security Action Memoranda, National Security Action Memoranda Number 50. John F. Kennedy Library Museum, Boston, Massachusetts
Public domain