158. “On the Formal Relation between the Riemann Curvature Tensor and the Field Equations of the Gravitational Field” “Über die formale Beziehung des Riemannschen Krümmungstensors zu den Feldgleichungen der Gravitation” [Einstein 1927a] Received 9 January 1926 Published after 30 October 1926 In: Mathematische Annalen 97 (1927): 99–103.