 Everett took a job outside academics as a defense analyst in the spring of 1956. While subsequent notes and letters indicate that he continued to be interested in the conceptual problems of quantum mechanics and, in particular, in the reception and interpretation of his formulation of the theory, he did not take an active role in the debates surrounding either. Consequently, the long version of his thesis (1956) is the most complete description of his theory. Everett died in 1982. See (Byrne 2010) for further biographical details and (Barrett and Byrne 2012) for an annotated collection of Everett’s papers, notes, and letters regarding quantum mechanics. See also (Osnaghi, Freitas, Freire 2009) for an excellent introduction to the history of Everett’s formulation of quantum mechanics.