Bebernes, J.; Gaines, R.; Schmitt, K. Existence of periodic solutions for third and fourth order ordinary differential equations via coincidence degree. (English) Zbl 0286.34056 Ann. Soc. Sci. Bruxelles, Sér. I 88, 25-36 (1974). Page: −5 −4 −3 −2 −1 ±0 +1 +2 +3 +4 +5 Show Scanned Page Cited in 6 Documents MSC: 34C25 Periodic solutions to ordinary differential equations 34B15 Nonlinear boundary value problems for ordinary differential equations 34A40 Differential inequalities involving functions of a single real variable PDFBibTeX XMLCite \textit{J. Bebernes} et al., Ann. Soc. Sci. Brux., Sér. I 88, 25--36 (1974; Zbl 0286.34056)