[1] Dahiya, R. S. and O. Akinyele, Oscillation theorems of n-th order functional differential equations with forcing terms, J. Math. Anal. Appl., 109(1985), 325-332.
[2] Foster, K. E. and R. C. Grimmer, Nonoscillatory solutions of higher order delay equations, J. Math. Anal Appl., 77(1980), 150-164.
[3] Grace, S. R. and B. S. Lalli, Oscillation theorems for n-th order delay differential equations, J. Math. Anal. Appl., 91(1983), 352-366.
[4] Grace, S. R. and B. S. Lalli, Asymptotic and oscillatory behavior of n-th order forced functional differential equations, J. Math. Anal. Appl., 140(1989), 10-25.
[5] Zilina, R. O., Oscillation of linear retarded differential equation, Czech. Math. J., 34(1984), 371-377.
[6] Liang Zhong-chao, A9ymptotically periodic solutions of a class of second order nonlinear differential equations, Proc. Anmr. Math. Soc., 99 (1987), 693-699.
[7] James S. W. Wong, Second order nonlinear forced oscillations, SIAM. J. Math. Anal., 19 (1988), 667-675. |