This paper is concerned with the oscillation criteria of solutions of the following quasilinear differential equation [phi u'(t))]' + c(t)phi(u(t)) = 0, where c(t) is a positive continuous function on [0,infinity) and phi(s) is a real-valued function defined by phi(s) = s\(p-2)s with p > 1 a fixed real number. These results extend some earlier oscillation criteria of Hille and Nehari by applying an inequality of Hardy's.
