12. “Proof of the Non-Existence of an Everywhere Regular, Centrally Symmetric Field According to the Field Theory of Kaluza” [Einstein and Grommer 1923a, 1923b] Received 10 January 1922 Published 1923 In: Scripta Universitatis atque Bibliothecae Hierosolymitanarum. Mathematica et Physica 1 (1923), VII: 1–5 Kitvei ha-Universita ve-Beth-ha-Sfarim bi-Yerushalayim. Mathematica u’Fisica. A (5684), VII: 1–4 (Hebrew).[1]