Oscillation criteria for forced second order quasi-linear PDE with damping

The oscillation criteria developed by Nasr and Wong are extended to the forced second order quasi-linear PDE with damping div(A(x)vertical bar del u vertical bar(p-2)del u) + (b(x),vertical bar del u vertical bar(p-2)del u) + c(x)vertical bar u vertical bar(q-2)u = e(x). When N = 1, for some forced second order nonlinear ordinary differential equations, our results include the recent results due to Li and and Cheng, Xing and Zheng, Yang, Zheng and Meng. When N >= 2, our results are more general, and improve the oscillation criteria of Zhuang for a forced second order undamped elliptic differential equation.