Symmetry in Nonlinear Mathematical Physics - 2009
Victor Robuk (Institute of Electrophysics and Radiation Technologies, Kharkov, Ukraine & Joint Institute for Nuclear Research,
A function of differential-matrix operator
Extending the results of  a method for construction of function of differential-matrix operator is proposed.
 V.N. Robuk, A constructive formula for function of matrix. Alternative to the Lagrange–Sylvester formula,
Nuclear Instruments and Methods in Physics Research, Section A 534 (2004), 319–323.