A note on Nasr’s and Wong’s papers

In the case of oscillatory potentials, we give sufficient conditions for the oscillation of the forced nonlinear second order differential equations with delayed argument in the form x (t )+ q(t) x(τ(t)) γ sgn x(τ(t)) = f (t) in the linear (γ = 1) and the superlinear (γ >1) cases.  2003 Elsevier Inc. All rights reserved