1. TNA, DEFE 25/325, AAP to Minister of State Trident: Amendment to Polaris Sales Agreement , 19 September 1980. On the classified annexes to the PSA see Kristan Stoddart, Losing an Empire and Finding a Role: Britain, the USA, NATO and Nuclear Weapons 1964–1970 (Basingstoke: Palgrave, 2012), pp. 32–33.
2. TNA, DEFE 25/325, B.M. Norbury PS/S OF S to Sec CNS , 7 November 1980. On the early management of Trident see also Colin McInnes, Trident: The Only Option? (London: Brassey’s 1986), pp. 77–78.
3. Berhanykun Andemicael and John Mathiason, Eliminating Weapons of Mass Destruction (Basingstoke: Palgrave, 2005).
4. House of Commons, Defence Committee Session 1980–81 Strategic Nuclear Weapons Policy, 26 November 1980, pp. 931–932.
5. Graham Spinardi, From Polaris to Trident: The Development of US Fleet Ballistic Missile Technology (Cambridge: Cambridge University Press, 1994), p. 142.