Memorandum from Russell Murray, Assistant Secretary of Defense (Program Analysts & Evaluation) to Secretary of Defense, “Interim Report on the PD-18 Study Modernization of the ICBM Force -- ACTION MEMORANDUM,” 26 June 1978, with “Introduction and Summary,” “Paper # 2 Launch-Under-Attack,” and “Paper #3 “The Strategic Options Matrix,” attached, Top Secret, excised copy