423. Foreword to Tuvia Schalit, Di spetsyele relativitets- teorye. Aynstayns shite un Minkovskis „velt“ [Einstein 1927c] Dated [after 30 November 1926][1] Published 1927 In: Tuvia Schalit. Di spetsyele relativitets-teorye. Aynstayns shite un Minkovskis “velt” (The Special Theory of Relativity: Einstein’s Theory and Minkowski’s “World”). Berlin: Eygener farlag (published by the author), 1927, n. p.