1. Albert Einstein, “Die Feldgleichungen der Gravitation,” Sitzungsberichte der Königlich Preussischen Akademie der Wissenschaften (1915), 844–47. Or “The Field Equations of Gravitation,” in The Collected Papers of Albert Einstein (hereafter CPAE), vol. 6, doc. 25,
http://einsteinpapers.press.princeton.edu/vol6-trans/129
.
2. Albert Einstein, letter to Willem de Sitter, March 12, 1917, CPAE, vol. 8, doc. 311,
http://einsteinpapers.press.princeton.edu/vol8-trans/329
.
3. Chris Smeenk, “Einstein’s Role in the Creation of Relativistic Cosmology,” in The Cambridge Companion to Einstein, ed. Michel. Janssen and Christoph Lehner (Cambridge: Cambridge University Press, 2014), 228–69.
4. Albert Einstein, “Kosmologische Betrachtungen zur allgemeinen Relativitätstheorie,” Sitzungsberichte der Königlich Preussischen Akademie der Wissenschaften (1917), 142–52. Or “Cosmological Considerations in the General Theory of Relativity,” CPAE, vol. 6, doc. 43,
https://einsteinpapers.press.princeton.edu/vol6-trans/433
.
5. Cormac O’Raifeartaigh, Michael O’Keeffe, Werner Nahm, and Simon Mitton, “Einstein’s 1917 Static Model of the Universe: A Centennial Review,” European Physical Journal H 42, no. 3 (2017), 431–74.