The resources below are books, articles, and other media that are useful references for aspects of this topic. When they are complete, each reference will be described and tagged. See here for an example of a more or less complete entry.
Conley, Jerome M. "Nuclear Command and Control in the Twenty-First Century: Trends, Disparities, and the Impact on Stability." In Debating 21st Century Nuclear Issues, edited by Owen Price and Jenifer Mackby, 226-250. Washington, D.C.: Center for International and Strategic Studies, 2007. https://www.csis.org/analysis/debating-21st-century-nuclear-issues.
Grossman, Elaine. "How Putin Might Yank Away Trump’s Control Over America’s Nuclear Weapons." War is Boring. July 3, 2017. https://warisboring.com/how-putin-might-yank-away-trumps-control-over-americas-nuclear-weapons/.
Hoffman, David E. "The Russian Nuclear Button: New questions about the Soviet legacy of three briefcases." Foreign Policy. May 27, 2010. https://foreignpolicy.com/2010/05/27/the-russian-nuclear-button-2/.
MacDonald, Eryn. "Whose Finger Is on the Button? Nuclear Launch Authority in the United States and Other Nations." Union of Concerned Scientists. October, 2017. https://www.ucsusa.org/sites/default/files/attach/2017/11/Launch-Authority.pdf.
Podvig, Pavel. "Risks of Nuclear Command and Control Accidents." In Understanding Nuclear Risks, edited by John Borrie, Tim Caughley, and Wilfred Wan, 53-59. Geneva, Switzerland: United Nations Institute for Disarmament Research (UNIDIR), 2017. http://www.unidir.org/files/publications/pdfs/understanding-nuclear-weapon-risks-en-676.pdf.