Functional differential equations, which include ordinary and delay differential equations, and integral equations have important roles in many scientific areas such as mechanics, engineering, economy, control theory, physics, chemistry, biology, medicine, atomic energy, and information theory. This special issue is concerned with qualitative behaviors of these equations. The qualitative behavior of equations includes oscillation, stability, periodicity, global attractivity, bifurcation analysis, control of chaos, and existence of solutions of integral equations. We aim to provide a platform for the discussion of the major research challenges and achievements on qualitative behaviors of solutions of these equations. Theoretical as well as application results are welcome.

Potential topics include, but are not limited to:

• Fractional differential equations
• Delay differential equations
• Neutral delay differential equations
• Distribution of zeros of differential equations and Lyapunov’s inequalities
• Different types of inequalities (Opial, Wirtinger, Grown-wall, Belmann, Halany, etc.)
• Rayleigh equation
• Volterra integral equations
• Lyapunov’s stability theory
• Asymptotic behavior (oscillation stability, periodicity, and global attractivity) of models
• Global existence of solutions
• Boundary value problems on unbounded intervals