Bifurcation of contracting singular cycles Rafael Labarca (1995) Annales scientifiques de l'École Normale Supérieure
Bifurcation of gradient mappings possessing the Palais-Smale condition. Tonkes, Elliot (2011) International Journal of Mathematics and Mathematical Sciences
Bifurcations and stability of families of diffeomorphisms Sheldon E. Newhouse, Jacob Palis, Floris Takens (1983) Publications Mathématiques de l'IHÉS