PageHeader : Funkcialaj Ekvacioj, 15 (1972), 61-73 Title : Existence of Quasi-Periodic Solutions of Title : Quasi-Periodic Systems AuthorInfo : By Fumio NAKAJIMA AuthorInfo : (Tohoku University) section : 1. Introduction. section : 2. Invariant periodic surfaces and quasi-periodic systems. section : 3. Proof of the theorem. section : Appendix section : References