Massera, Jose L. The existence of periodic solutions of systems of differential equations. (English) Zbl 0038.25002 Duke Math. J. 17, 457-475 (1950). Page: −5 −4 −3 −2 −1 ±0 +1 +2 +3 +4 +5 Show Scanned Page Cited in 5 ReviewsCited in 163 Documents Keywords:Ordinary differential equations PDFBibTeX XMLCite \textit{J. L. Massera}, Duke Math. J. 17, 457--475 (1950; Zbl 0038.25002) Full Text: DOI