1. D. Chen, Oscillatory behavior of a class of fractional differential equations with damping, U.P.B. Sci. Bull., Series A, 2013, 75(1),107-118.
2. D. X. Chen, P. X. Qu and Y. H. Lan,Forced oscillation of certain fractional differential equations, Adv. Differ. Equ., 2013, 2013(1), 125.
3. Q. Feng and F. Meng, Oscillation of solutions to nonlinear forced fractional differential equations, Electron. J. Differ. Eq., 2013, 2013(169), 1471-1484.
4. S. R. Grace, R. P. Agarwal, P. J. Y. Wong, et al, On the oscillation of fractional differential equations. Fract. Calc. Appl. Anal., 2012, 15(2), 222-231.
5. Z. Han, Y. Zhao, S. Ying, et al, Oscillation Theorem for a Kind of Fractional Differential Equations, Journal of Binzhou University, 2013, 2013(9-10), 216-219.