1. Isolated invariant sets and the Morse index;Conley;CBMS Regional Conference Series in Mathematics,1978
2. Generalized recurrence in dynamical systems;Auslander;Contr. diff. Eqns,1964
3. Differentiable Dynamics;Nitecki,1971
4. Differential equations with a multivalued discontinuous right-hand side;Filippov;Dokl. Akad. Nauk SSSR,1963
5. On Zeeman's tolerance stability conjecture;Takens,1971