Conservation laws, soliton solutions and modulational instability for the higher-order dispersive nonlinear Schrödinger equationHai-Qiang Zhang, Bo Tian, Xiang-Hua Meng, Xing Lü and Wen-Jun LiuEur. Phys. J. B, 72 2 (2009) 233-239DOI: https://doi.org/10.1140/epjb/e2009-00356-3