Lax pair, conservation laws and N-soliton solutions for the extended Korteweg-de Vries equations in fluidsPan Wang, Bo Tian, Wen-Jun Liu, Qi-Xing Qu, Min Li and Kun SunEur. Phys. J. D, 61 3 (2011) 701-708DOI: https://doi.org/10.1140/epjd/e2010-10357-x