N.V. Alexeeva, I.V. Barashenkov, and
D.E. Pelinovsky,Dynamics of the parametrically driven NLS
solitons beyond the onset of the oscillatory instability,Nonlinearity12,103-140(1999)
D.E. Pelinovsky, J.E. Sipe, and J. Yang,Generation of Soliton Oscillation in Nonlinear
Quadratic Materials,Phys. Rev. E59,7250-7253(1999)