Smith P. A singular perturbation method for saddle connections and subitarmonie of certain nonlinear differential equations with fixed saddle points. Rev. mat. complut. [Internet]. 1 de enero de 1990 [citado 31 de julio de 2026];3(1):89. Disponible en: https://revistas.ucm.es/index.php/REMA/article/view/REMA9090120089A