M. Chaperon, S. López de Medrano, C. Watts and E. C. Zeeman:
Almost invariant probability measures for diffeomorphisms and flows on a compact Riemannian manifold, and the associated notion of structural stability.
Comptes Rendus de l'Académie des Sciences, Série 1, Mathématique, 307/1 (1988): 95-100.