具正负系数和阻尼项的高阶泛函微分方程的振动性
杨甲山
Oscillation of higher order functional differential equations with positive and negative coefficients and damping term
YANG Jia-Shan
华东师范大学学报（自然科学版） . 2014, (6): 25 -34 .  DOI: 10.3969/j.issn.1000-5641.2014.06.005