Singular Separatrix Splitting and the Melnikov Method: An Experimental Study. - Amadeu Delshams; Rafael Ramírez-Ros (Exp. Math., 1999)

Separatrix Splitting in 3D Volume-Preserving Maps. - Héctor E. Lomelí; Rafael Ramírez-Ros (SIAM J. Appl. Dyn. Syst., 2008)

The Frequency Map for Billiards inside Ellipsoids. - Pablo S. Casas; Rafael Ramírez-Ros (SIAM J. Appl. Dyn. Syst., 2011)