Which mathematician was the father of physicist Nikolai Borisovich Delone: Jakow Trachtenberg or Boris Delaunay?
Jakow Trachtenberg Jakow Trachtenberg (17 June 1888 – 1953) was a Jewish mathematician who developed the mental calculation techniques called the Trachtenberg system.
Nikolai Brashman Nikolai Dmitrievich Brashman (Russian: Николáй Дми́триевич Брáшман ; German: "Nikolaus Braschmann" ; June 14, 1796 – 25 May [O.S. 13 May] 1866 ) was a Russian mathematician of Austrian origin. He was a student of Joseph Johann Littrow, and the advisor of Pafnuty Chebyshev and August Davidov.