On the oscillatory properties of certain fourth order nonlinear difference equations

Some new criteria for the oscillation of fourth order nonlinear difference equations of the form 1 a3(n) 1 a2(n) 1 a1(n) x(n) α1 α2 α3 +δq(n)f x g(n) = 0, where δ =±1 are investigated. © 2005 Elsevier Inc. All rights reserved.