References
- Arino , O. and Gyöi , I. 1989 . Necessary and suficient condition for oscillation of a neutral differential system with several delays . J . Differ. Eqns. , 81 : 98 – 105 .
- Chen , Y. 1989 . Oscillation of a class of neutral functional differential equations . Chin. Ann. Math. , 10A ( 5 ) : 545 – 553 .
- Gopalsamy , K. and Zhang , B.G. 1990 . Oscillation and nonoscillation in first order neutral differential equations. . J . Math. Anal. Appl. , 151 : 42 – 57 .
- Grernmatikpoulos , M.K. , Grove , E.A. and Ladas , G. 1986 . Oscillation and asymptotic behavior of neutral differential equations with deviating arguments . Applicable Anal. , 22 : 1 – 19 .
- Huang , W. 1990 . Necessary and suficient conditions for o~cillation of first-order functional differential equations . J. Math. Anal. Appl. , 148 : 360 – 370 .
- Stavroulakis , I.P. 1989 . Oscillations of mized neutral equations . Hiroshima Math. J . , 19 : 441 – 456 .