The present paper deals with the problem of the construction of the difference formulae for the solution of the ordinary differential equation of the first order from the given characteristic polynomial, with the effect of the choice of zeros of the characteristic polunomial on the local error of the difference methods for the equation $y'=Ay,\ y(0)=1,\ A$ being a constant, and with the dependence of the error constant on the choice of zeros of the characteristic polynomial in the general case.
 Henrici P.: Discrete variable methods in differential equations
. Wiley, New York-London 1962. MR 0135729
 Voňka P.: Stability of difference methods. Thesis, Charles Univ., Fac. of Math. Phys., Dept. of Numerical Math. 1968. (Czech, unpublished.)