TURKISH JOURNAL OF MATHEMATICS, cilt.36, sa.3, ss.422-436, 2012 (SCI-Expanded)
Third-order nonlinear difference equations of the form Delta(c(n)Delta(d(n)Delta x(n))) p(n)Delta x(n+1) + q(n)f (x(n-sigma)) = n >= n(0) are considered. Here, {c(n)}, {d(n)}, {p(n)} and {q(n)} are sequences of positive real numbers for n(0) is an element of N, f is a continuous function such that f(u)/u >= K > 0 for u not equal 0. By means of a Riccati transformation technique we obtain some new oscillation criteria. Examples are given to illustrate the importance of the results.