Ige. Kordonis et Cg. Philos, OSCILLATION OF NEUTRAL DIFFERENCE-EQUATIONS WITH PERIODIC COEFFICIENTS, Computers & mathematics with applications, 33(7), 1997, pp. 11-27
Two classes of neutral linear difference equations with periodic coeff
icients are considered, and necessary conditions and also sufficient c
onditions for the oscillation of all solutions are established. These
conditions are referred to the roots of the associated characteristic
equations.