PageHeader : Funkcialaj Ekvacioj, 23 (1980), 143-149 Title : On the Existence of Periodic Solutions for Nonlinear Title : Ordinary Differential Equations in Banach Spaces AuthorInfo : By AuthorInfo : Shigeo KATO AuthorInfo : (Kitami Institute of Technology, Japan) section : 1. Introduction section : 2. Preliminaries section : 3. Main Results section : 4. Example section : References