Oscillation of first order delay differential equations with distributed delay. (Q1425120)

The author considers the first-order delay differential equation with distributed delay \[ x'(t)+\int_0^{b(t)}R(t,s)x(t-s)\,d\mu(s)=0,\tag{1} \] the first-order nonlinear delay differential equation with distributed delay \[ x'(t)+\int_0^bR(t,s)f(x(t-s))\,d\mu(s)=0,\tag{2} \] and the higher-order delay differential equation \[ x^{(m)}(t)=(-1)^m\sum_{i=1}^np_i(t)x(t-\tau_i).\tag{3} \] Oscillation criteria for equations (1), (2), and (3) are established.