時の門
↑ heinleinarchives.net
↑ Heinlein does not explain the etymology of "diktor". Bob White, in Fictional Languages (Ch. 3), points out that the title could have developed as a convergence of "doctor", "director" and "dictator", as the functions of a "diktor" include a bit of all three.
↑ "The Paradoxes of Time Travel", American Philosophical Quarterly, April (1976): pp. 145–152
↑ Sagan, Carl (1978年5月28日). “Growing up with Science Fiction” (英語). The New York Times: p. SM7. ISSN 0362-4331. https://www.nytimes.com/1978/05/28/archives/growing-up-with.html 2018年12月12日閲覧。