A survey of G. J. Butler's research in the qualitative theory of ordinary differential equations (Q803362)

A short survey of the main results obtained by the late Professor G. J. Butler in the domain of differential equations mentioned in the title is given. The survey consists of five sections: 1. Introduction, 2. Periodic solutions of second order nonlinear differential equations, 3. Oscillation and nonoscillation for second order differential equations, 4. Comparison theorems and oscillation for higher order linear equations and systems, 5. Concluding remarks (some miscellaneous contributions in chaotic behavior of mappings and fixed point theorems and packing and covering problems).