Some oscillation criteria for the second order retarded differential equation [r(t)\u'(t)\(alpha-1)u'(t)]' + p(t)\u(tau(t))\(beta-1)u(tau(t)) = 0 are given, where alpha and beta are positive constants, and p, tau, r is an element of C([t(0), infinity), R) satisfy some suitable conditions. Our results generalize those of Erbe, Ohriska and Lakshmikatham.
