An oscillation criterion for functional differential equations with deviating arguments (Q5917665)

The author gives an oscillation criterion for the differential equation \[ {d \over dt} {1 \over a_{n - 1} (t)} {d \over dt} \cdots {d \over dt} {1 \over q_1(t)} {d \over dt} x(t) + f \biggl( t,x \bigl[ g_1(t) \bigr], \dots, x \bigl[ g_m(t) \bigr] \biggr) = 0, \] \(n\) even. The obtained result is new even for \(a_i (t) \equiv 1\), \(i = 1, \dots, n - 1\).