Smale flows on $\mathbb{S}^2\times\mathbb{S}^1$
  In this paper, we use abstract Lyapunov graphs as a combinatorial tool to obtain a complete classification of Smale flows on $\mathbb{S}^2\times\mathbb{S}^1$. This classification gives necessary and sufficient conditions that must be satisfied by an abstract Lyapunov graph in order for it to be associated to a Smale flow on $\mathbb{S}^2\times\mathbb{S}^1$. 
Ketty A. de Rezende, Guido G. E. Ledesma and Oziride M. Neto
math.DS