Multiple solutions of the forced double pendulum equation

Fournier, G.; Willem, M.

Annales de l'I.H.P. Analyse non linéaire, Volume 6 (1989) p. 259-281

A PDE approach to certain large deviation problems for systems of parabolic equations

Evans, L. C.; Souganidis, P. E.; Fournier, G.; Willem, M.

Annales de l'I.H.P. Analyse non linéaire, Volume 6 (1989) p. 229-258

Critical points of convex perturbations of some indefinite quadratic forms and semi-linear boundary value problems at resonance

Mawhin, J.; Willem, M.

Annales de l'I.H.P. Analyse non linéaire, Volume 3 (1986) p. 431-453