1. On a class of functionals invariant under a Zn;Rabinowitz;Trans. Am. math. Soc.,1988
2. On the periodic nonlinearity and the multiplicity of solutions;Chang;Nonlinear Analysis,1989
3. Multiple periodic solutions of conservative systems with periodic nonlinearity;Fonda,1989
4. The Birkhoff-Lewis fixed point theorem and a conjecture of V. Arnold;Conley;Invent. Math.,1983
5. Forced oscillations for the triple pendulum;Chang;ETH Zürich Report,1988