Some Applications of Generalized Mountain Pass Lemma
  The Ghoussoub-Preiss's generalized Mountain Pass Lemma with Cerami-Palais-Smale type condition is a generalization of classical MPL of Ambrosetti-Rabinowitz, we apply it to study the existence of the periodic solutions with a given energy for some second order Hamiltonian systems with symmetrical and non-symmetrical potentials. 
Fengying Li and Bingyu Li and Shiqing Zhang
math.FA math.DS