Were Pavel Urysohn and Leonid Levin known for the same type of work?
Leonid Levin Leonid Anatolievich Levin ( ; Russian: Леони́д Анато́льевич Ле́вин ; Ukrainian: Леоні́д Анато́лійович Ле́він ; born November 2, 1948) is a Soviet-American computer scientist.
Nikolai Ushin Nikolai Alexeyevich Ushin (Russian: Николай Алексеевич Ушин , 1898 – 6 April 1942) was a Soviet graphic artist, theatre designer and book illustrator.