Asymptotic Behavior of a Class of Fourth Order Nonlinear Functional Differential Equation with Delays

In paper [1,2], Onose and Kusano have discussed the equation r ( t ) y ″ ( t ) ′ ′ + f ( t , y ( g ( t ) ) ) = 0 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9781003067498/6ba0c26b-f086-40cc-86ed-1693dc596221/content/eq5258.tif"/>