Kulzhumiyeva, A.A., and Zh.A. Sartabanov. “On Reducibility of Linear De-System With Constant Coefficients on the Diagonal to De-System With Jordan Matrix in the Case of Equivalence of Its Higher Order One Equation”. Bulletin of the Karaganda University. Mathematics Series, vol. 84, no. 4, Dec. 2016, pp. 88-93, doi:10.31489/2016m4/88-93.