The distribution of zeros of solutions for a class of neutral delay differential equations

In this paper, the distribution of zeros of solutions of neutral differential equations[x(t)-cx(t-γ)]′+P(t)x(t-τ)=0,[x(t)-cx(t-γ)]′+P(t)x(t-τ)=0,where c > 0, τ, γ > 0 and P ∈ C([t0, +∞), R+), are studied, and some estimates for the distance between adjacent zeros of the oscillatory solutions of the above equation are obtained.