[1] Reissig R, Sansone G, Conti R. Nonlinear Differential Equations of Higher Order[M], Noordhoff International Publishing, 1974. [2] Afuwape A U. Ultimate boundedness results for a certain system of third order nonlinear differential equations[J]. J Math Anal Appl, 1983, 97:140-150. [3] Ezeilo J O C. J Math Anal Appl, 1967, 18:395-416. [4] Ezeilo J O C. New properties of the equation x + ax + bx+ h(x)= p(t, x, x, x)for certain special values of the incrementary ratio y-1{ h(x+y)-h(x)} [A]. In:P Janssens, J Mawhin, N Rouche eds. Equations Diffirentielles et Fonctionelles Nonlineaires [C]. Paris:Hermann, 1973, 447-462. [5] Ezeilo J O C, Tejumola H O. Atti Accad Naz Lincei Renol Cl Sci Fis Mat Natur [M]. 1975, 50:143-151. [6] Meng F W. Ultimate boundedness results for a certain system of third order nonlinear differential equations [J]. J Math Anal Appl, 1993, 177:496-509. [7] Tunc C. A global stability result for a certain system of fifth order nonlinear differential equations[J] University of Marmara, The Journal of Sciences, 10 (in Press). [8] Browder F E. On a generalization of the Schauder fixed point theorem[J]. Duke Math J, 1959, 26:291-303. [9] Tiryaki A, Tunc C. Boundedness and stability properties of solutions of certain fourth order differential equations via the intrinsic method[J]. Analysis, 1996, 16:325-334. [10)Tunc C. A ultimate boundedness result for the solutions of certain fifth order nonlinear differential equations[J]. PUJM, 1997, 30. [11] Yoshizawa T. Stability Theory and the Existence of Periodic Solutions and Almost Periodic Solutions [M]. New York/Heidelberg:Springer-Verlag, 1978 |