Characteristics of lump solutions to a (3 + 1)-dimensional variable-coefficient generalized shallow water wave equation in oceanography and atmospheric scienceJian-Guo Liu, Wen-Hui Zhu, Yan He and Zhi-Qiang LeiEur. Phys. J. Plus, 134 8 (2019) 385DOI: https://doi.org/10.1140/epjp/i2019-12799-2