On the oscillation of certain functional differential equations via comparison methods (Q1414217)

Several oscillation criteria for functional-differential equations of the form \[ \frac{d}{dt}\left( \left[ \frac{1}{a_{n-1}(t)}\frac{d}{dt} \frac{1}{a_{n-2}(t)}\frac{d}{dt}\dots\frac{1}{a_{1}(t)}\frac{d}{dt}x(t) \right] ^{a}\right) \pm q(t)f(x[g(t)])=0 \] are established.