The calculation for characteristic multiplier of Hill's equation in case q(t) < 0. - Jinlin Shi; Aizhi Weng; Jiyang Chen (Appl. Math. Comput., 2005)

Oscillation of second order delay differential equations. - Aizhi Weng; Jitao Sun (Appl. Math. Comput., 2008)

Impulsive stabilization of second-order nonlinear delay differential systems. - Aizhi Weng; Jitao Sun (Appl. Math. Comput., 2009)