Bernstein, Aaron (1897). "Eine Phantasie-Reise im Weltall" [A fantasy trip in space]. Naturwissenschaftliche Volksbücher [Popular Books on Natural Science]. Vol. 16. p. 54. Retrieved 8 September 2012.
newyorker.com
Canales, Jimena (20 November 2015). "Albert Einstein's Sci-Fi Stories". The New Yorker. Also see Jimena Canales, The Physicist and the Philosopher: Einstein, Bergson and the Debate That Changed Our Understanding of Time (Princeton Press, 2015).