%0 Journal Article
%T The unsolved riddle of Selim Krein
%A Kaplan, A..
%K methods of teaching mathematics, art of the lecturer. 
%J Actual directions of scientific researches of the XXI century: theory and practice
%D 2014
%N 2
%P 1
%I FSBE Institution of Higher Education Voronezh State University of Forestry and Technologies named after G.F. Morozov