Z. Jiang and W. Ma, Permanence of a delayed SIR epidemic model with general nonlinear incidence rate, Math. Methods Appl. Sci., (38)2015, 505–516..

B. G. Sampath Aruna Pradeep and W. Ma, Stability properties of a delayed HIV dynamics model with Beddington - Deangelis functional response and absorption effect, Dyn. Contin. Discrete Impul. Syst., Series A: Math. Anal., 21 (2014), 421-434..

Z. Jiang, W. Ma and D. Li, Dynamical behavior of a delay differential equation system on toxin producing phytoplankton and zooplankton interaction, Japan J. Indust. Appl. Math., 31( 2014), 583-609..

C. Fu and W. Ma, Partial stability of some guidance dynamic systems with delayed line-of-sight angular rate, Int. J. Control, Auto., Syst., 12(2014), 1234-1244..

Q. Dong and W. Ma, Qualitative analysis of a chemostat model with inhibitory exponential substrate uptake and a time delay, Int. J. Biomath., 7(2014), 1450045 (16 pages)..

S. Guo, W. Ma and B. G. Sampath Aruna Pradeep, Necessary and sufficient conditions for oscillation of neutral delay differential equations, Elect. J. Differ. Equations, 2014 (2014), No. 138, 1-12..

Z. Hu, W. Pang, F. Liao and W. Ma, Analysis of a CD4+ T cell viral infection model with a class of saturated infection rate, Discrete Contin. Dyn. Syst.-B, 19(2014), 735-745..

S. Guo and W. Ma, Complete characterizations of the gamma function, Appl. Math. Comput., 244 (2014), 912–916..

Z. Hu, J. Zhang, H. Wang, W. Ma and F. Liao, Dynamics analysis of a delayed viral infection model with logistic growth and immune impairment, Appl. Math. Modelling, 38 (2014), 524–534..

D. Li, W. Ma and Z. Jiang, An epidemic model for Tick-Borne disease with two delays, J. Appl. Math., Volume 2013, Article ID 419593, 12 pages..