References
- Grammatikopoulos , M.K. , Sficas , Y.G. and Stavroulakis , I.P. Necessary and sufficient conditions for oscillations of neutral equations with several coefficients , to appear : J. Differential Egns .
- Grove , E.A. , Ladas , G. and Schultz , S.W. 1988 . Oscillations and asymptotic behavior of first-order neutral delay differential equations . Applicable Analysis , 27 : 67 – 78 .
- Kulenovic , M.R.S. , Ladas , G. and Meimaridou , A. 1987 . Necessary and sufficient conditions for oscillations of neutral differential equations . J. Austral. Math. Soc., Series B , 28 : 362 – 375 .
- Ladas , G. , Sficas , Y.G. and Stavroulakis , I.P. 1983 . Necessary and sufficient conditions for oscillation . Amer. Math. Monthly , 90 : 637 – 640 .