1. A. Einstein, Die Grundlage der allgemeinen Relativitätstheorie. Annalen der Physik 49, (1916). New publication of the original English translation ([2]) in [3]
2. A. Einstein, The foundation of the general theory of relativity, in The Principle of Relativity: A Collection of Original Memoirs on the Special and General Theory of Relativity, ed. by H.A. Lorentz, A. Einstein, H. Minkowski, H. Weyl. With Notes by A. Sommerfeld. Translated by W. Perrett and G.B. Jeffery (Methuen and Company, Ltd., 1923; reprinted by Dover Publications Inc., 1952)
3. V. Petkov (ed.), The Origin of Spacetime Physics, 2nd edn. Foreword by A. Ashtekar. (Minkowski Institute Press, Montreal, 2023)
4. K. Schwarzschild, On the gravitational field of a mass point according to Einstein’s theory. Sitzungsber. K. Preuss. Akad. Wiss. 1, 189 (1916)
5. D. Finkelstein, Past-future asymmetry of the gravitational field of a point particle. Phys. Rev. 110, 965 (1958)