[1] GYORI I.-LADAS G.:
Oscillation Theory of Delay Differential Equations with Applications. Clarendon Press, Oxford, 1991.
MR 1168471
[2] KUSANO T.-NAITO M.:
Non-linear oscillation of fourth order differential equations. Canad. J. Math. 4 (1976), 840-852.
MR 0430415
[3] KUSANO T.-NAITO M.:
On fourth order non-linear oscillations. J. London Math. Soc. (2) 14 (1976), 91-105.
MR 0447706 |
Zbl 0385.34014
[4] PARHI N.-RATH R. N.:
On oscillation of solutions of forced non-linear neutral differential equations of higher order. Czechoslovak Math. J. (To appear).
MR 2018832
[5] PARHI N.-RATH R. N.:
On oscillation criteria for forced non-linear higher order neutral differential equations. Math. Slovaca 54 (2004), 369-388.
MR 2102290
[6] PARHI N.-TRIPATHY A. K.:
On oscillatory fourth order non-linear neutral differential equations I. Math. Slovaca 54 (2004), 389-410.
MR 2102291