Are both Sergei Sobolev and Mikhail Leonidovich Gromov members of the IHÉS in France?
Sergei Sobolev Sergei Lvovich Sobolev (Russian: Серге́й Льво́вич Со́болев ; 6 October 1908 – 3 January 1989) was a Soviet mathematician working in mathematical analysis and partial differential equations. He was born in St. Petersburg, and died in Moscow.
Eugeniusz Grodziński Eugeniusz Grodziński (January 10, 1912, Pskov, Russia - October 11, 1994,