I have been review the finite difference for long wave family equation (RLW, Rosenau-kawahara, etc) and see that the boundedness and convergence always imply the stability of the proposed difference scheme
The list of some reviewed paper are
- Hu, Jinsong, et al. "Two conservative difference schemes for Rosenau-Kawahara equation." Advances in Mathematical Physics 2014 (2014).
- Pan, Xintian, Kelong Zheng, and Luming Zhang. "Finite difference discretization of the Rosenau-RLW equation." Applicable Analysis 92.12 (2013): 2578-2589.