1. Nonconservative positional system—stability;Barone-Netto;Dynamics Stability Systems,1988
2. Hill's Equation;Magnus,1966
3. Liapunov stability for some central forces;Zampieri;J. Differential Equations,1988
4. Solving a collection of free coexistence-like problems in stability;Zampieri,1989
5. The last free coexistence-like problem;Zampieri;Differential Integral Equations,1990