MARTEL, Y.; MERLE, F. Note on Coupled Linear Systems Related to Two Soliton Collision for the Quartic gKdV Equation. Revista Matemática Complutense, v. 21, n. 2, p. 327–350, 15 jul.2008 https://doi.org/10.5209/rev_REMA.2008.v21.n2.16378.