Differential Equations, 28 (1992) 6, 794-800. Reviews: MR 93j:34072, ZM 834.34059.
In this paper we consider a generalization of a result of a Cartwright and Swinnerton-Dyer on the dissipativity (ultimate boundedness of solutions) of the autonomous Lienard equation x''+f(x,x')x'+g(x)=0. We extend this result to include nonautonomous spaces of solutions due to V. V. Filippov. This allows us to consider the generalized Lienard equation x''+f(x,x')x'+g(x)=e(t,x,x') with relaxed restrictions on f and g, and f, g, and e with arbitrary singularities. We also prove the existence of periodic solutions through the Brouwer Fixed Point Theorem.