Similarities in the bifurcation diagrams of three systems that permit escape from a potential well under parametric excitation are related to horseshoe formation in the invariant manifolds of the hill-top saddles. © 1993.
Clifford, M. J., & Bishop, S. R. (1993). Generic features of escape from a potential well under parametric excitation. Physics Letters A, 184(1), 57–63. https://doi.org/10.1016/0375-9601(93)90346-2