The collaboration on the second volume of that work, published in 1939, continued even after 1933; face to face collaboration ceased sometime in 1934 when Bernays moved to Zürich. Otto Blumenthal, who had converted to Protestantism when he was 18, lost his position at RWTH Aachen University. NSDAP In the mid-1930s, racist Nazi policies that limited the participation of Jewish mathematicians were imposed on the German mathematics journal Zentralblatt für Mathematik. Ivan Niven identified this as a turning point for the journal saying it began to "deteriorate". Otto Neugebauer, who had been a key figure in founding Zentralblatt, had moved to the United States and taken a position at Brown University. With his expertise a new reviewing journal, Mathematical Reviews, was established in the United States. During the years of Nazi rule, many classes in German universities would begin with a Nazi salute, a practice that Erich Hecke declined to implement in his classroom. Even before Hitler's rise to power, some mathematicians had already emigrated to the United States for various reasons. John von Neumann had taken a position at the California Institute of Technology in 1929 because he felt anti-semitism in Germany was affecting his career. By 1933, von Neumann had a position at Princeton; though he had maintained ties with Germany until then, he canceled his scheduled lectures in Berlin after Hitler became Chancellor.
The collaboration on the second volume of that work, published in 1939, continued even after 1933; face to face collaboration ceased sometime in 1934 when Bernays moved to Zürich. Otto Blumenthal, who had converted to Protestantism when he was 18, lost his position at RWTH Aachen University. NSDAP
 In the mid-1930s, racist Nazi policies that limited the participation of Jewish mathematicians were imposed on the German mathematics journal Zentralblatt für Mathematik. Ivan Niven identified this as a turning point for the journal saying it began to "deteriorate". Otto Neugebauer, who had been a key figure in founding Zentralblatt, had moved to the United States and taken a position at Brown University. With his expertise a new reviewing journal, Mathematical Reviews, was established in the United States. During the years of Nazi rule, many classes in German universities would begin with a Nazi salute, a practice that Erich Hecke declined to implement in his classroom. Even before Hitler's rise to power, some mathematicians had already emigrated to the United States for various reasons. J.  von Neumann had taken a position at the California Institute of Technology in 1929 because they felt anti-semitism in Germany was affecting their career. By 1933, von Neumann had a position at Princeton; though they had maintained ties with Germany until then, they canceled their scheduled lectures in Berlin after Hitler became Chancellor.