Oscillation Theorems for Nonlinear Second Order Elliptic Equations

Some oscillation theorems are given for the nonlinear second order elliptic equation\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$ {\sum\limits_{i,j = 1}^N {D_{i} {\left[ {a_{{ij}} {\left( x \right)}\Psi {\left( y \right)}{\left\| {\nabla y} \right\|}^{{p - 2}} D_{j} y} \right]}} } + c{\left( x \right)}f{\left( y \right)} = 0. $$\end{document} The results are extensions of modified Riccati techniques and include recent results of Usami.