"1973Z"^^ . "German physicist" . "Erich Justus Kretschmann (July 14, 1887 in Berlin \u2013 1973) was a German physicist.He obtained his D.Phil. at Berlin University in 1914 with his dissertation entitled \"Eine Theorie der Schwerkraft im Rahmen der urspr\u00FCnglichen Einsteinschen Relativit\u00E4tstheorie (A theory of gravity in the framework of the original Einstein theory of relativity)\". His advisors were Max Planck and Heinrich Rubens."@en . "1887-07-14Z"^^ . "1887Z"^^ . "Kretschmann, Erich"@en .