Asymptotic behavior and oscillations of second order differential equations with deviating argument (Q1916727)

The equation \[ (a(t)x')+ b(t)x'(t)+ c(t)x(t)= f(t,x(t),x'(t), x(\Phi(t)), x'(\Phi(t)))\tag{1} \] is considered, where \(a,b,c,\Phi\) are continuous functions defined on \(\mathbb{R}_+\) and \(f\) is continuous on \(\mathbb{R}_+\times \mathbb{R}^4\). Under certain restrictions, the behaviour of solutions of (1) as \(t\to+\infty\) is studied.