[1] Ladas G, SFICAS Y D. Oscillations of higher_order equations [J]. Journal of the Australian Mathematical Society 1986, 27. [2] Bainov D D, MISHEV D P. Oscillation Theory for neutral differential equations with Delay [M]. Bristol:Adam Hilger 1992. [3] Erbe L H, KONG Q K, ZHANG B G. Oscillation theory for functional differential equations [M]. New York:Marcel Dekker 1995. [4] GRACE S R. Oscillation of even order nonlinear functional differential equation with deviatiing arguments [J]. Funkcialaj Ekvacioj Journal 1989, 32. [5] GRACE S R. Oscillation theorems of comparison type for neutral nonlinear functional differential equation [J]. Czechoslovak Mathematical Journal 1995, 45(04). [6] 燕居让. 高阶中立型方程振动性的比较定理及应用 [J]. 中国科学A辑 1990, 12. [7] 陈永劭. 关于高阶中立型泛函微分方程的振动性 [J]. 1992. [8] WSNG P G, FU X L, YU Y H. Oscillations of solution for a class of higher order neutral differential equation [J]. Applied Mathematical Journal of Chinese University 1998, 13(04). [9] KIGURADZE I T. On the oscillation of solutions of the equation /+a|u|nsgnu=0 [J]. Mat Sb 1964, 65. [10] GRACE S R, LALLI B S. Oscillation theorems for damped differential equations of even order with deviating arguments [J]. SIAM Journal on Mathematical Analysis 1984, 15(02). |